Faculty Profiles - NAGANAWA, Shinji

Predictive factors for the outcomes of initial I-131 low-dose ablation therapy to Japanese patients with differentiated thyroid cancer. Reviewed

Shinji Ito, Shingo Iwano, Katsuhiko Kato, Shinji Naganawa

Annals of nuclear medicine Vol. 32 ( 6 ) page： 418 - 424 2018.7

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: To identify prognostic factors associated with a low-iodine diet (LID) and the amount of remnant thyroid tissue in Japanese patients with differentiated thyroid cancer (DTC) who received initial I-131 remnant ablation (RAI) using a fixed low dose of I-131 (1110 MBq). PATIENTS AND METHODS: In this prospective study, we enrolled 45 patients. Patients were classified into a self-managed LID group and a strict LID group. We measured the urinary iodine concentration on the day of RAI after patients consumed LID for 2 weeks. Thyroid-stimulating hormone-induced thyroglobulin (Tg) levels and I-131 uptake by the remnant thyroid tissue were also evaluated. A response-evaluation whole-body scan (WBS) was performed 6-8 months after RAI to determine the outcome of the therapy. RESULTS: Post-LID urinary iodine levels of the strict LID group tended to be lower than those of the self-managed LID group. Twenty-five cases (56%) showed absence of uptake, whereas 20 cases (44%) showed residual uptake on the response-evaluation WBS. There were no significant differences between "absence" and "residual" groups in urinary iodine concentrations and Tg levels (p = 0.253 and p = 0.234, respectively). However, significant differences were observed in I-131 uptake by the thyroid bed (p = 0.035). CONCLUSIONS: For patients following the current Japanese method of a 2-week LID, the urinary iodine concentration was not a predictive factor for the successful outcome of RAI. In contrast, low I-131 uptake by the thyroid bed, revealed by the scintigram after RAI, may serve as a favorable predictive factor.

DOI： 10.1007/s12149-018-1261-0

Myocardial motion analysis based on an optical flow method using tagged MR images. Reviewed

Daiki Tabata, Haruo Isoda, Kaori Kato, Hiroki Matsubara, Takafumi Kosugi, Takashi Kosugi, Masaki Terada, Atsushi Fukuyama, Yoshiaki Komori, Shinji Naganawa

Radiological physics and technology Vol. 11 ( 2 ) page： 202 - 211 2018.6

Language：English Publishing type：Research paper (scientific journal)

We developed a method of velocimetry based on an optical flow method using quantitative analyses of tagged magnetic resonance (MR) images (tagged MR-optical flow velocimetry, tMR-O velocimetry). The purpose of our study was to examine the accuracy of measurement of the proposed tMR-O velocimetry. We performed retrospective pseudo-electrocardiogram (ECG) gating tagged cine MR imaging on a rotating phantom. We optimized imaging parameters for tagged MR imaging, and validated the accuracy of tMR-O velocimetry. Our results indicated that the difference between the reference velocities and the computed velocities measured using optimal imaging parameters was less than 1%. In addition, we performed tMR-O velocimetry and echocardiography on 10 healthy volunteers, for four sections of the heart (apical, midventricular, and basal sections aligned with the short-axis, and a four-chamber section aligned with the long-axis), and obtained radial and longitudinal myocardial velocities in these sections. We compared the myocardial velocities obtained using tMR-O velocimetry with those obtained using echocardiography. Our results showed good agreement between tMR-O velocimetry and echocardiography in the radial myocardial velocities in three short-axial sections and longitudinal myocardial velocities on the midventricular portion of the four-chamber section in the long-axis. In the study conducted on the rotating phantom, tMR-O velocimetry showed high accuracy; moreover, in the healthy volunteers, the myocardial velocities obtained using tMR-O velocimetry were relatively similar to those obtained using echocardiography. In conclusion, tMR-O velocimetry is a potentially feasible method for analyzing myocardial motion in the human heart.

DOI： 10.1007/s12194-018-0456-3

Study Protocol: Prospective Study of Concurrent Chemoradiotherapy with S-1 and Hypofractionated Radiotherapy for Outpatients with Early Glottic Squamous Cell Carcinomas Reviewed International journal

Kana Kimura, Yoshiyuki Itoh, Tohru Okada, Seiji Kubota, Mariko Kawamura, Rie Nakahara, Yumi Oie, Yuka Kozai, Yuuki Takase, Hidenori Tsuzuki, Naoki Nishio, Mariko Hiramatsu, Yasushi Fujimoto, Takefumi Mizutani, Akihiro Hirakawa, Shinji Naganawa

Asian Pacific journal of cancer prevention : APJCP Vol. 19 ( 5 ) page： 1195 - 1199 2018.5

Language：English Publishing type：Research paper (scientific journal)

Background: The recommended treatment strategies for early glottic carcinoma with intent of larynx preservation are
primarily radiotherapy. However, the outcomes of radiotherapy for bulky T1 or T2 glottic carcinoma are unsatisfactory.
We designed a protocol consisting of concurrent chemoradiotherapy using S-1 as the radiosensitizer. We have performed
this protocol in patients with favorable T2 lesions and demonstrated its efficacy and safety. In contrast, we have
treated non-bulky T1 glottic carcinomas with 2.25 Gy per fraction, for a total of 25-28 fractions, starting in 2011 to
improve efficacy and shorten the treatment period. Since this treatment strategy was implemented for T1 disease, no
local failure has occurred to date, and it appears to be almost as safe as radiotherapy using 2.0 Gy per fraction. With
the aim of improving the local control rate and shortening the treatment period primarily for favorable T2 disease, we
changed the dose of radiation in our protocol from 2.0 Gy to 2.25 Gy per fraction, for a total of 25 fractions (from 30
fractions). The present study aims to evaluate the efficacy and safety of this new protocol. Methods: This study will
be conducted as a clinical, prospective, single-armed, non-randomized trial. Patients are to receive S-1 (55.3 mg /m2
/day, once daily) and radiotherapy (2.25 Gy per fraction, for a total of 25 fractions). S-1 and radiotherapy are started
on the same day that radiotherapy is performed, 3-6 hours after oral administration of S-1. The primary study aim is
the 3-year local control rate. The secondary study aims are overall survival, voice-preservation survival, disease-free
survival, complete response rate, completion rate, and toxicity. Result and conclusion: This is the first single-center,
non-randomized, prospective study of concurrent chemoradiotherapy with S-1 and hypofractionated radiotherapy to
be conducted. The trial will evaluate the efficacy and safety of our protocol.

DOI： 10.22034/APJCP.2018.19.5.1195

Evaluation of the tumoricidal and pain relief effects of Sr-89 on bone metastases of cancer by F-18-fluoride PET/CT, F-18-FDG PET/CT, bone scintigraphy/SPECT, and follow-up Reviewed

Kato Katsuhiko, Odagawa Tetsuro, Fujita Naotoshi, Tsutsumi Yoshinori, Matsuzawa Shinichiro, Mukumoto Ryuto, Hasegawa Chinatsu, Abe Shinji, Naganawa Shinji

JOURNAL OF NUCLEAR MEDICINE Vol. 59 page： . 2018.5

Efficacy of percutaneous transhepatic portal vein embolization using gelatin sponge particles and metal coils. Reviewed International journal

Tomohiro Komada, Kojiro Suzuki, Takashi Mizuno, Tomoki Ebata, Masaya Matsushima, Shinji Naganawa, Masato Nagino

Acta radiologica open Vol. 7 ( 4 ) page： 2058460118769687 - 2058460118769687 2018.4

Language：English Publishing type：Research paper (scientific journal)

Background: Percutaneous transhepatic portal vein embolization (PTPE) can increase the future liver remnant (FLR) volume before extended liver resection; however, there is no current consensus regarding the best embolic material for PTPE. Purpose: To evaluate the efficacy of PTPE using gelatin sponge particles and coils. Material and Methods: The medical records of 136 patients who underwent PTPE using gelatin sponge particles and metal coils were retrospectively reviewed. We evaluated the procedural details, liver volume on CT, and clinical status before and after PTPE. Results: The mean FLR volume increased significantly from 390 ± 147 cm3 to 508 ± 141 cm3 (P < 0.001). A mean of 22.1 ± 9.4 days after PTPE, the mean increase in the ratio of FLR volume to total liver volume was 9.4 ± 6.5%. Complications related to PTPE occurred in five patients, including arterial damage (n = 4) and biloma (n = 1). The white blood cell count and C-reactive protein level increased significantly and then returned to baseline within seven days. Aspartate aminotransferase and alanine aminotransferase showed no significant changes. Fever (defined by the Common Terminology Criteria for Adverse Events v4.0) was reported in 74 patients (54%), but it was generally mild (Grade 1/2; n = 72). None of the patients experienced severe complications that required cancellation of surgery. Conclusion: PTPE with gelatin sponge particles and coils may impose low physical stress on patients and is a safe method of inducing a significant increase of FLR.

DOI： 10.1177/2058460118769687

FDG PET/CT Overcomes Discordance Between Clinical and Pathologic TNM Classification of Small-size Primary Lung Cancer: Influence on Postoperative Prognosis. Reviewed International journal Open Access

Hiroyasu Umakoshi, Shingo Iwano, Kohei Yokoi, Shinji Ito, Rintaro Ito, Koji Kawaguchi, Takayuki Fukui, Shinji Naganawa

Clinical lung cancer Vol. 19 ( 1 ) page： e37 - e45 2018.1

Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: We aimed to determine the concordance between the clinical stage (c-stage) and pathologic stage (p-stage) for patients with small-size lung cancer. Additionally we searched for prognostic factors other than the TNM stage. PATIENTS AND METHODS: We retrospectively reviewed the preoperative multidetector computed tomography (CT) and positron emission tomography/CT reports, surgical records, and pathologic reports of patients with primary lung cancer ≤ 3 cm. The Union for International Cancer Control TNM seventh edition classification of c-stage and p-stage were compared. The tumors were classified into multiple subgroups by concordance or discordance between the c-stage and p-stage. Disease-free survival (DFS) was assessed using survival analysis to assess the tumor characteristics that were predictive of prognosis. RESULTS: A total of 289 surgically resected primary lung cancers were evaluated. The concordance between c-stage and p-stage was 65.4%, with moderate reproducibility (kappa coefficient, 0.467). The upstaging rate from c-stage I to p-stage II-IV was 9.4%, and these patients had significantly worse DFS than those with a concordant stage I classification (P < .001). The main reason for upstaging was an underestimation of metastases to the hilar lymph nodes (n = 7) or mediastinal lymph nodes (n = 11). A multivariate Cox proportional hazards model showed that the significant predictive factors for DFS were p-stage (hazard ratio, 1.342; P = .003) and maximum standardized uptake value on positron emission tomography/CT (hazard ratio, 12.162; P = .001). CONCLUSION: The concordance rate between c-stage and p-stage for small primary lung cancers had moderate reproducibility. Discordance between c-stage I and p-stage II-IV significantly affected DFS. The maximum standardized uptake value of the primary lesion was an independent prognostic factor, and combining it with c-stage might improve the prediction of therapeutic outcomes.

DOI： 10.1016/j.cllc.2017.05.021

Three-dimensional printer-generated patient-specific phantom for artificial in vivo dosimetry in radiotherapy quality assurance. Reviewed International journal Open Access

Takeshi Kamomae, Hidetoshi Shimizu, Takayoshi Nakaya, Kuniyasu Okudaira, Takahiro Aoyama, Hiroshi Oguchi, Masataka Komori, Mariko Kawamura, Kazuhiro Ohtakara, Hajime Monzen, Yoshiyuki Itoh, Shinji Naganawa

Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) Vol. 44 page： 205 - 211 2017.12

Language：English Publishing type：Research paper (scientific journal)

Pretreatment intensity-modulated radiotherapy quality assurance is performed using simple rectangular or cylindrical phantoms; thus, the dosimetric errors caused by complex patient-specific anatomy are absent in the evaluation objects. In this study, we construct a system for generating patient-specific three-dimensional (3D)-printed phantoms for radiotherapy dosimetry. An anthropomorphic head phantom containing the bone and hollow of the paranasal sinus is scanned by computed tomography (CT). Based on surface rendering data, a patient-specific phantom is formed using a fused-deposition-modeling-based 3D printer, with a polylactic acid filament as the printing material. Radiophotoluminescence glass dosimeters can be inserted in the 3D-printed phantom. The phantom shape, CT value, and absorbed doses are compared between the actual and 3D-printed phantoms. The shape difference between the actual and printed phantoms is less than 1 mm except in the bottom surface region. The average CT value of the infill region in the 3D-printed phantom is -6 ± 18 Hounsfield units (HU) and that of the vertical shell region is 126 ± 18 HU. When the same plans were irradiated, the dose differences were generally less than 2%. These results demonstrate the feasibility of the 3D-printed phantom for artificial in vivo dosimetry in radiotherapy quality assurance.

DOI： 10.1016/j.ejmp.2017.10.005

Structural MRI correlates of amyotrophic lateral sclerosis progression. Reviewed International journal Open Access

Joe Senda, Naoki Atsuta, Hirohisa Watanabe, Epifanio Bagarinao, Kazunori Imai, Daichi Yokoi, Yuichi Riku, Michihito Masuda, Ryoichi Nakamura, Hazuki Watanabe, Mizuki Ito, Masahisa Katsuno, Shinji Naganawa, Gen Sobue

Journal of neurology, neurosurgery, and psychiatry Vol. 88 ( 11 ) page： 901 - 907 2017.11

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Amyotrophic lateral sclerosis (ALS) presents with varying degrees of brain degeneration that can extend beyond the corticospinal tract (CST). Furthermore, the clinical course and progression of ALS varies widely. Brain degeneration detected using structural MRI could reflect disease progression. SUBJECTS AND METHODS: On study registration, 3-Tesla volumetric MRI and diffusion tensor imaging scans were obtained at baseline in 38 healthy controls and 67 patients with sporadic ALS. Patients had Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) scores of ≥36 and did not have the chromosome 9, open reading frame 72 repeat expansion. Six months later, changes in ALSFRS-R (ΔALSFRS-R) scores were calculated and patients were grouped into three categories, namely, patients with slow progression with ΔALSFRS-R scores ≤3 (n=19), intermediate progression with ΔALSFRS-R scores =4, 5 and 6 (n=36) and rapid progression with ΔALSFRS-R scores ≥7 (n=12). We analysed voxel-based morphometry and tract-based spatial statistics among these subgroups and controls. RESULTS: In comparison with controls, patients with ALS showed grey matter atrophy and decreased fractional anisotropy beyond the motor cortex and CST, especially in the frontotemporal lobes and basal ganglia. Moreover, the degree of change was highly proportional to ΔALSFRS-R at the 6-month assessment. CONCLUSION: A more rapid disease progression and poorer functional decline were associated with greater involvement of the extra-motor cortex and basal ganglia, suggesting that the spatial extent of brain involvement can be an indicator of the progression in ALS.

DOI： 10.1136/jnnp-2016-314337

Comparison of I-123-IMP SPECT, F-18-FDG PET/CT, and F-18-FDOPA PET/CT in Detection of Choroidal Malignant Melanoma Reviewed

Kato K., Odagawa T., Tsutsumi T., Honda M., Kunimoto K., Mukumoto R., Matsuzawa S., Abe S., Naganawa S.

EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING Vol. 44 page： S745 - S745 2017.10

Penetration and distribution of gadolinium-based contrast agents into the cerebrospinal fluid in healthy rats: a potential pathway of entry into the brain tissue Reviewed International coauthorship International journal Open Access

Gregor Jost, Thomas Frenzel, Jessica Lohrke, Diana Constanze Lenhard, Shinji Naganawa, Hubertus Pietsch

EUROPEAN RADIOLOGY Vol. 27 ( 7 ) page： 2877 - 2885 2017.7

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Signal hyperintensity on unenhanced MRI in certain brain regions has been reported after multiple administrations of some, but not all, gadolinium-based contrast agents (GBCAs). One potential initial pathway of GBCA entry into the brain, infiltration from blood into the cerebrospinal fluid (CSF), was systematically evaluated in this preclinical study.
GBCA infiltration and distribution in the CSF were investigated in healthy rats using repeated fluid-attenuated MRI up to 4 h after high-dose (1.8 mmol/kg) administration of six marketed and one experimental GBCA. Additionally, gadolinium measurements in CSF, blood and brain tissue samples (after 24 h) were performed using inductively coupled plasma mass spectrometry.
Enhanced MRI signals in the CSF spaces with similar distribution kinetics were observed for all GBCAs. No substantial differences in the gadolinium concentrations among the marketed GBCAs were found in the CSF, blood or brain tissue. After 4.5 h, the concentration in the CSF was clearly higher than in blood but was almost completely cleared and lower than the brain tissue concentration after 24 h.
In contrast to the brain signal hyperintensities, no differences in penetration and distribution into the CSF of healthy rats exist among the marketed GBCAs.
aEuro cent Gadolinium-based contrast agents can cross the blood-CSF barrier.
aEuro cent Fluid-attenuated MRI shows GBCA distribution with CSF flow.
aEuro cent GBCA structure and physicochemical properties do not impact CSF penetration and distribution.
aEuro cent GBCA clearance from CSF was almost complete within 24 h in rats.
aEuro cent CSF is a potential pathway of GBCA entry into the brain.

DOI： 10.1007/s00330-016-4654-2

Clinical outcome of definitive radiation therapy for superficial esophageal cancer. Invited International journal

Yutaro Koide, Takeshi Kodaira, Hiroyuki Tachibana, Natsuo Tomita, Chiyoko Makita, Makoto Itoh, Tetsuya Abe, Kei Muro, Masahiro Tajika, Yasumasa Niwa, Yoshiyuki Itoh, Shinji Naganawa

Japanese journal of clinical oncology Vol. 47 ( 5 ) page： 393 - 400 2017.5

Language：English Publishing type：Research paper (scientific journal)

Objective: To analyze the clinical outcome of concurrent chemoradiotherapy in superficial esophageal cancer patients. Methods: We retrospectively analyzed data for 123 patients with superficial esophageal cancer who received external beam radiotherapy without intracavitary brachytherapy plus systemic chemotherapy during 1998-2015. Elective nodal irradiation was not performed. The dosage to planning treatment volume was 60 Gy in 30 fractions. The main outcome measure was overall survival. Results: Patient characteristics were as follows: median age, 66 (41-83) years; male/female ratio, 106/17; squamous cell carcinoma/other, 122/1; cT1a/cT1b, 27/96; cervical esophagus/upper thoracic esophagus/middle thoracic esophagus/lower thoracic esophagus, 7/9/66/41 and concurrent chemoradiotherapy/radiotherapy alone, 100/23. Cisplatin and 5-fluorouracil were the most commonly used agents (85%). At the last follow-up (median 60.5 months), 91 (74%) patients were alive. Complete response was achieved in 116 (94.4%) patients. The 5-year overall survival, progression-free survival and local control rates were 77.0, 46.9 and 62.7%, respectively, similar to that in the elderly patients (P = 0.878, 0.754 and 0.648, respectively). There were 55 failures: 42 local, 10 regional and 3 distant failures. Nine local and seven regional failures developed out-of-field. Thirty-eight local failures (90%) were successfully salvaged, of which 30 (71%) were salvaged via endoscopic removal; only 2 regional failures (20%) were salvaged. Fifteen G3 acute toxicities occurred. One pneumonitis (G3), one pneumothorax (G3) and two pericardial effusion (G2) were the late toxicities observed. There were no G4 toxicities or treatment-related deaths. Conclusions: Concurrent chemoradiotherapy without intracavitary brachytherapy was effective and safe for superficial esophageal cancer, even in elderly patients.

DOI： 10.1093/jjco/hyx021

Magnetic resonance imaging evaluation of endolymphatic hydrops andpost-operative findings in cases with otosclerosis Reviewed

Michihiko Sone, Tadao Yoshida, Satofumi Sugimoto, Kyoko Morimoto, Yuriko Okazaki, Masaaki Teranishi, Shinji Naganawa, Tsutomu Nakashima

ACTA OTO-LARYNGOLOGICA Vol. 137 ( 3 ) page： 242 - 245 2017.3

Language：English Publishing type：Research paper (scientific journal) Publisher：TAYLOR & FRANCIS LTD

Conclusions: The presence of endolymphatic hydrops (EH) in the vestibule on magnetic resonance imaging (MRI) might be a high-risk factor for complications in cases that are candidates for stapes surgery.
Objective: Pre-operative detection of EH could be valuable in cases that are candidates for stapes surgery to prevent unpredictable complications following surgery. Pre-operative MRI findings and post-operative findings following stapes surgery were compared to evaluate the efficacy of such MRI evaluation for the management of cases with otosclerosis.
Subjects and methods: Sixteen cases who underwent pre-operative evaluation by 3T MRI performed 4h after intravenous injection of gadolinium and stapes surgery for otosclerosis were recruited. Imaging data concerning the degree of EH in the vestibule and cochlea were compared with post-operative clinical findings for all cases.
Results: Mild EH in the cochlea or the vestibule was observed in eight ears and one ear, respectively, whereas one ear showed significant EH both in the cochlea and the vestibule. The post-operative course was uneventful in 12 of 14 cases with no EH in the vestibule, and the other two cases had a short period of dizziness, but two cases with EH in the vestibule had a long period of dizziness.

DOI： 10.1080/00016489.2016.1232862

Postoperative chemoradiation therapy using high dose cisplatin and fluorouracil for high- and intermediate-risk uterine cervical cancer. Reviewed Open Access

Rise Miyauchi, Yoshiyuki Itoh, Mariko Kawamura, Akihiro Hirakawa, Kiyosumi Shibata, Hiroaki Kajiyama, Rie Nakahara, Seiji Kubota, Junji Ito, Tohru Okada, Fumitaka Kikkawa, Shinji Naganawa

Nagoya journal of medical science Vol. 79 ( 2 ) page： 211 - 220 2017.2

Language：English Publishing type：Research paper (scientific journal)

The purpose of this retrospective study was to analyze data in patients with stage IB-IIB uterine cervical cancer who were treated with concurrent chemoradiotherapy (CCRT) with high dose cisplatin and fluorouracil as postoperative adjuvant therapy. Between February 2003 and November 2011, 76 patients with FIGO stage IB-IIB cervical cancer were analyzed. Seventy patients were treated with postoperative CCRT and 6 patients were treated with radiation therapy alone. Data related to overall survival (OS), disease-free survival (DFS), toxicity, and failure pattern were analyzed. The median patient age was 45 years (range, 20-80 years). The median follow-up duration was 63 months (range, 10-125 months). Fifty-eight patients (76.3%) had a squamous cell histologic type, 55 patients (72.4%) had lymphovascular invasion, 31 patients (40.8%) had parametrial invasion, and 28 patients (36.8%) had lymph node metastases. Five-year OS and DFS were 96% and 92%, respectively. Five-year DFS in stage IB1 patients was significantly higher than in stage IB2-IIB patients (p = 0.022). Nineteen patients (25%) had grade 3 or 4 neutropenia, 13 patients (17.1%) had grade 3 anemia, and 2 patients (2.6%) had grade 3 thrombocytopenia, but none of these patients died from the disease. Three patients experienced chronic toxicity: one had bladder perforation, one had hydronephrosis, and one experienced ileus. CCRT as postoperative adjuvant therapy resulted in good survival and outcome without severe toxicity.

DOI： 10.18999/nagjms.79.2.211

Structure of the Medullary Veins of the Cerebral Hemisphere and Related Disorders Reviewed

Toshiaki Taoka, Akio Fukusumi, Toshiteru Miyasaka, Hisashi Kawai, Toshiki Nakane, Kimihiko Kichikawa, Shinji Naganawa

RADIOGRAPHICS Vol. 37 ( 1 ) page： 281 - 297 2017.1

Language：English Publishing type：Research paper (scientific journal) Publisher：RADIOLOGICAL SOC NORTH AMERICA

Deep medullary veins drain into subependymal veins with four convergence zones and show parallel distribution patterns adjacent to the body or inferior horn and a radial pattern in the frontal horn or trigon of the lateral ventricle. As white matter imaging develops such as diffusion tensor imaging or susceptibility-weighted imaging, requirements for understanding of white matter structures are increasing, not only for understanding of neuronal tracts but also for that of other structures including the fine anatomy of white matter vessels. Some disorders are related to deep medullary veins and show characteristic distributions of the lesions indicating the relationship to the medullary veins. When lesions show a parallel or radial distribution pattern in the certebral deep white matter, disorders related to deep medullary veins should be considered for differential diagnosis. In this review, we discuss disorders related to deep medullary veins, including (a) anomalies of the medullary veins, (b) hemorrhagic disorders related to the medullary veins (diffuse vascular injury due to high-energy trauma, deep medullary vein engorgement/thrombosis in neonates), (c) inflammatory changes that spread along the medullary veins, (d) neoplasms within the medullary veins, and (e) metabolic changes that lead to altered visualization of medullary veins. Understanding the anatomic structure of medullary veins in the cerebral hemisphere and becoming familiar with disorders in which the medullary veins play a major role in disease development may be helpful in the interpretation of brain images. (C) RSNA, 2017

DOI： 10.1148/rg.2017160061

Endolymphatic hydrops in patients with unilateral and bilateral Meniere's disease Reviewed

Kyoko Morimoto, Tadao Yoshida, Saiko Sugiura, Masahiro Kato, Ken Kato, Masaaki Teranishi, Shinji Naganawa, Tsutomu Nakashima, Michihiko Sone

ACTA OTO-LARYNGOLOGICA Vol. 137 ( 1 ) page： 23 - 28 2017.1

Language：English Publishing type：Research paper (scientific journal) Publisher：TAYLOR & FRANCIS LTD

Conclusion: All definite Meniere's disease (MD) had endolymphatic hydrops (EH) at least in the cochlea or the vestibule. Symptoms of MD may appear after formation of EH. It is assumed that the probability of immediate progression to bilateral MD from unilateral MD is very low in patients without EH on the non-affected side.
Objective: To evaluate the EH on both sides in patients with unilateral and bilateral MD, and to investigate factors with progression to bilateral MD including the degree of EH, hearing level, and the duration of MD.
Patients and methods: The study included 29 patients with unilateral definite MD and 12 patients with bilateral definite MD. The endolymphatic space size was visualized by using 3-Tesla magnetic resonance imaging.
Results: All patients with unilateral and bilateral MD had significant or mild EH at least in the cochlea or the vestibule on the affected side. On the non-affected side, EH was not observed at all in eight patients, but asymptomatic EH was observed in the cochlea in 14 patients and in the vestibule in 16 patients. There was no relationship between the EH on the non-affected side and the duration of MD.

DOI： 10.1080/00016489.2016.1217042

Repeat stereotactic radiosurgery for recurrent brain metastases: a retrospective comparison of local progression and distant brain metastases after prior radiosurgery Reviewed

Emerging neuroradiological topics in journals from related societies Reviewed Open Access

Yukunori Korogi, Shinji Naganawa

JAPANESE JOURNAL OF RADIOLOGY Vol. 35 ( 1 ) page： 1 - 2 2017.1

Diffuse but Non-homogeneous Brain Atrophy: Identification of Specific Brain Regions and Their Correlation with Clinical Severity in Rett Syndrome Reviewed Open Access

Hajime Narita, Jun Natsume, Takeshi Suzuki, Tadashi Shiohama, Masahiro Kawaguchi, Masaki Okazaki, Atsushi Hashizume, Shinji Naganawa, Yuji Ito, Hiroyuki Yamamoto, Tomohiko Nakata, Hiroyuki Kidokoro, Yoshiyuki Takahashi, Satoru Takahashi, Keita Tsujimura

Brain and Development Vol. 47 ( 3 ) page： 104348 - 104348 2025.6

Masamune Noguchi, Yutaro Koide, Yurika Shindo, Takahiro Aoyama, Shingo Hashimoto, Hiroyuki Tachibana, Takeshi Kodaira, Shunichi Ishihara, Shinji Naganawa

Journal of Neuro-Oncology 2025.4

Magnetic resonance imaging indices for early Alzheimer's disease detection: Brain clearance markers. Reviewed International journal Open Access

Moto Nakaya, Koji Kamagata, Kaito Takabayashi, Christina Andica, Wataru Uchida, Akifumi Hagiwara, Toshiaki Akashi, Akihiko Wada, Toshiaki Taoka, Shinji Naganawa, Osamu Abe, Shigeki Aoki

Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism page： 271678X251321305 2025.3

Language：English Publishing type：Research paper (scientific journal)

The Alzheimer's disease (AD) continuum is characterized by amyloid and tau protein deposition, which is partly attributable to the dysfunction of the brain clearance system. However, the specific phase in the AD continuum wherein aberrant clearance is present remains unclear. This study aimed to assess noninvasive magnetic resonance imaging (MRI) indices related to brain clearance functions, such as choroid plexus volume (CPV), lateral ventricular volume (LVV), and the index of diffusivity along the perivascular space (ALPS index), across the Alzheimer's disease (AD) spectrum. The CPV, LVV, and ALPS index in amyloid beta (Aβ)-negative healthy controls (HCs) and Aβ-positive HCs as well as in patients with Aβ-negative subjective cognitive decline (SCD), with Aβ-positive SCD, with mild cognitive impairment, and with AD were evaluated. The CPV and LVV were higher, whereas the ALPS index was lower in the patients with more severe disease. The ALPS index was significantly lower in Aβ-positive HCs than in Aβ-negative HCs. In SCD patients and those in the AD continuum, the MRI-based clearance markers were correlated with P-tau and T-tau protein levels and cognitive scores. In summary, brain clearance markers on MRI are associated with tau deposition, neurodegeneration and cognitive dysfunction.

DOI： 10.1177/0271678X251321305

Advancing clinical MRI exams with artificial intelligence: Japan’s contributions and future prospects Reviewed Open Access

Shohei Fujita, Yasutaka Fushimi, Rintaro Ito, Yusuke Matsui, Fuminari Tatsugami, Tomoyuki Fujioka, Daiju Ueda, Noriyuki Fujima, Kenji Hirata, Takahiro Tsuboyama, Taiki Nozaki, Masahiro Yanagawa, Koji Kamagata, Mariko Kawamura, Akira Yamada, Takeshi Nakaura, Shinji Naganawa

Japanese Journal of Radiology Vol. 43 ( 3 ) page： 355 - 364 2025.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

Abstract

In this narrative review, we review the applications of artificial intelligence (AI) into clinical magnetic resonance imaging (MRI) exams, with a particular focus on Japan’s contributions to this field. In the first part of the review, we introduce the various applications of AI in optimizing different aspects of the MRI process, including scan protocols, patient preparation, image acquisition, image reconstruction, and postprocessing techniques. Additionally, we examine AI’s growing influence in clinical decision-making, particularly in areas such as segmentation, radiation therapy planning, and reporting assistance. By emphasizing studies conducted in Japan, we highlight the nation’s contributions to the advancement of AI in MRI. In the latter part of the review, we highlight the characteristics that make Japan a unique environment for the development and implementation of AI in MRI examinations. Japan’s healthcare landscape is distinguished by several key factors that collectively create a fertile ground for AI research and development. Notably, Japan boasts one of the highest densities of MRI scanners per capita globally, ensuring widespread access to the exam. Japan’s national health insurance system plays a pivotal role by providing MRI scans to all citizens irrespective of socioeconomic status, which facilitates the collection of inclusive and unbiased imaging data across a diverse population. Japan’s extensive health screening programs, coupled with collaborative research initiatives like the Japan Medical Imaging Database (J-MID), enable the aggregation and sharing of large, high-quality datasets. With its technological expertise and healthcare infrastructure, Japan is well-positioned to make meaningful contributions to the MRI–AI domain. The collaborative efforts of researchers, clinicians, and technology experts, including those in Japan, will continue to advance the future of AI in clinical MRI, potentially leading to improvements in patient care and healthcare efficiency.

DOI： 10.1007/s11604-024-01689-y

Recent topics in musculoskeletal imaging focused on clinical applications of AI: How should radiologists approach and use AI? Reviewed

Other Link： https://link.springer.com/article/10.1007/s11604-024-01689-y/fulltext.html

Taiki Nozaki, Masahiro Hashimoto, Daiju Ueda, Shohei Fujita, Yasutaka Fushimi, Koji Kamagata, Yusuke Matsui, Rintaro Ito, Takahiro Tsuboyama, Fuminari Tatsugami, Noriyuki Fujima, Kenji Hirata, Masahiro Yanagawa, Akira Yamada, Tomoyuki Fujioka, Mariko Kawamura, Takeshi Nakaura, Shinji Naganawa

La radiologia medica 2025.2

MR Imaging Indices for Brain Interstitial Fluid Dynamics and the Effects of Orexin Antagonists on Sleep. Reviewed Open Access

Toshiaki Taoka, Kunihiro Iwamoto, Seiko Miyata, Rintaro Ito, Rei Nakamichi, Toshiki Nakane, Ippei Okada, Kazushige Ichikawa, Hirohito Kan, Koji Kamagata, Junko Kikuta, Shigeki Aoki, Akihiro Fujimoto, Yuki Kogo, Nobuyasu Ichinose, Shinji Naganawa, Norio Ozaki

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 2025.2

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The purpose of this study was to assess the extent to which improvement in sleep with lemborexant contributed to changes in interstitial fluid dynamics. METHODS: The 3 methods including diffusion tensor image analysis along the perivascular space (DTI-ALPS), dynamic contrast-enhanced method to assess tissue vascular permeability (Ktrans), and choroid plexus volume (CPV) were used. Correlations between these imaging indices and sleep parameters (latency to persistent sleep [LPS], wake after sleep onset [WASO], total sleep time [TST], and sleep efficiency [SE]) were evaluated using Pearson correlation analysis. Additionally, multiple regression analysis and linear mixed model analysis were employed to assess the relationship between baseline sleep status and imaging parameter changes. MRI and sleep assessments were performed before treatment initiation (week 0, w0) and at 12 weeks after lemborexant administration (week 12, w12). RESULTS: The ALPS-index was inversely correlated with LPS and positively correlated with TST and SE at w0. In multiple regression analysis, ALPS-index was lower when sleep parameters other than LPS were poor at w0. A linear mixed model analysis suggested that poor sleep status in LPS and SE at w0 may have an effect on greater ALPS-index. In the evaluation of Ktrans measurement, the single regression analysis showed a statistically significant correlation between the reduction in Ktrans and the shortening in LPS. Examination of CPV and sleep parameters showed a significant negative correlation between TST and CPV at w0 and w12. Multiple regression analysis also showed that TST of w12 had a significant effect on CPV at w12. CONCLUSION: Our results suggested that poor sleep status is related to the greater change of ALPS-index and CPV improvement after lemborexant administration may be related to in part to sleep parameter improvement.

DOI： 10.2463/mrms.mp.2024-0176

Applications of artificial intelligence in interventional oncology: An up-to-date review of the literature Reviewed Open Access

Yusuke Matsui, Daiju Ueda, Shohei Fujita, Yasutaka Fushimi, Takahiro Tsuboyama, Koji Kamagata, Rintaro Ito, Masahiro Yanagawa, Akira Yamada, Mariko Kawamura, Takeshi Nakaura, Noriyuki Fujima, Taiki Nozaki, Fuminari Tatsugami, Tomoyuki Fujioka, Kenji Hirata, Shinji Naganawa

Japanese Journal of Radiology Vol. 43 ( 2 ) page： 164 - 176 2025.2

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

Abstract

Interventional oncology provides image-guided therapies, including transarterial tumor embolization and percutaneous tumor ablation, for malignant tumors in a minimally invasive manner. As in other medical fields, the application of artificial intelligence (AI) in interventional oncology has garnered significant attention. This narrative review describes the current state of AI applications in interventional oncology based on recent literature. A literature search revealed a rapid increase in the number of studies relevant to this topic recently. Investigators have attempted to use AI for various tasks, including automatic segmentation of organs, tumors, and treatment areas; treatment simulation; improvement of intraprocedural image quality; prediction of treatment outcomes; and detection of post-treatment recurrence. Among these, the AI-based prediction of treatment outcomes has been the most studied. Various deep and conventional machine learning algorithms have been proposed for these tasks. Radiomics has often been incorporated into prediction and detection models. Current literature suggests that AI is potentially useful in various aspects of interventional oncology, from treatment planning to post-treatment follow-up. However, most AI-based methods discussed in this review are still at the research stage, and few have been implemented in clinical practice. To achieve widespread adoption of AI technologies in interventional oncology procedures, further research on their reliability and clinical utility is necessary. Nevertheless, considering the rapid research progress in this field, various AI technologies will be integrated into interventional oncology practices in the near future.

DOI： 10.1007/s11604-024-01668-3

Other Link： https://link.springer.com/article/10.1007/s11604-024-01668-3/fulltext.html

Diagnostic utility of chest wall vessel involvement sign on ultra-high-resolution CT for primary lung cancer infiltrating the chest wall. Reviewed International journal Open Access

Fuga Uota, Shingo Iwano, Shinichiro Kamiya, Rintaro Ito, Shota Nakamura, Toyofumi Fengshi Chen-Yoshikawa, Shinji Naganawa

European radiology 2025.1

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVES: Chest wall infiltration in primary lung cancer affects the surgical and therapeutic strategies. This study evaluates the efficacy of the chest wall vessel involvement in subpleural lung cancer (CWVI) on ultra-high-resolution CT (UHR-CT) for detecting chest wall invasion. MATERIALS AND METHODS: A retrospective analysis of lung cancer cases with confirmed pleural and chest wall invasion was conducted from November 2019 to April 2022. Seventy-seven patients (mean ± standard deviation age 70 ± 8 years, 64 males) who underwent preoperative contrast-enhanced UHR-CT were included. They were grouped into 51 non-chest wall infiltration (pl1 and pl2) and 26 chest wall infiltration (pl3). Clinical, histopathological, and UHR-CT findings were reviewed. RESULTS: Upper lobe tumors exhibited a higher chest wall invasion rate (p < 0.001). Rib destruction was evident in five patients with chest wall invasion but none with pleural invasion (p < 0.001). CWVI was present in 19 of 26 patients with chest wall invasion and 2 of 51 patients with pleural invasion (p < 0.001). The maximum tumor diameter (Dmax), arch distance which means the interface length between the primary tumor and the chest wall (Adist), and the ratio of Dmax to Adist were higher in chest wall invasion cases (all p < 0.001). After excluding patients with rib destruction, in multivariate logistic regression analysis, only CWVI was a significant predictor for chest wall invasion (odds ratio 29.22 (95% confidence interval 9.13-262.90), p < 0.001). CONCLUSION: CWVI on UHR-CT can help diagnose lung cancer infiltrating the chest wall, offering a potential tool for clinical decision-making. KEY POINTS: Question Chest wall infiltration in primary lung cancer has implications for the treatment plan, but diagnosis is often difficult with conventional CT. Findings Chest wall vessel involvement in subpleural lung cancer on ultra-high-resolution CT is a valuable predictor for diagnosing chest wall infiltration. Clinical relevance The delineation of chest wall vessels with contrast-enhanced ultra-high-resolution CT may improve the diagnosis of chest wall infiltration and allow accurate staging and optimal treatment options for subpleural primary lung cancer.

DOI： 10.1007/s00330-025-11382-x

Intracranial Air Absorption through Arachnoid Granulation: New Considerations from Transsphenoidal Surgery and Implications for Neurofluid Dynamics. Reviewed Open Access

Shinji Naganawa, Rintaro Ito, Mariko Kawamura, Toshiaki Taoka

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 24 ( 1 ) page： 144 - 147 2025

Language：English Publishing type：Research paper (scientific journal)

Postsurgery intracranial air usually diminishes, presumably merging with cerebrospinal fluid (CSF) and venous circulation. Our study presents two transsphenoidal surgery cases, highlighting potential air absorption by arachnoid granulation (AG)-an underexplored phenomenon. AG has long been deemed pivotal for CSF absorption, but recent perspectives suggest a significant role in waste clearance, neuroinflammation, and neuroimmunity. These cases may stimulate renewed research on the multifaceted role of AG in neurofluid dynamics and potentially elucidate further AG functions.

DOI： 10.2463/mrms.bc.2023-0122

Stereotactic arrhythmia radioablation for ventricular tachycardia: a review of clinical trials and emerging roles of imaging Reviewed Open Access

Mariko Kawamura, Masafumi Shimojo, Fuminari Tatsugami, Kenji Hirata, Shohei Fujita, Daiju Ueda, Yusuke Matsui, Yasutaka Fushimi, Tomoyuki Fujioka, Taiki Nozaki, Akira Yamada, Rintaro Ito, Noriyuki Fujima, Masahiro Yanagawa, Takeshi Nakaura, Takahiro Tsuboyama, Koji Kamagata, Shinji Naganawa

Journal of Radiation Research Vol. 66 ( 1 ) page： 1 - 9 2024.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Oxford University Press (OUP)

ABSTRACT

Ventricular tachycardia (VT) is a severe arrhythmia commonly treated with implantable cardioverter defibrillators, antiarrhythmic drugs and catheter ablation (CA). Although CA is effective in reducing recurrent VT, its impact on survival remains uncertain, especially in patients with extensive scarring. Stereotactic arrhythmia radioablation (STAR) has emerged as a novel treatment for VT in patients unresponsive to CA, leveraging techniques from stereotactic body radiation therapy used in cancer treatments. Recent clinical trials and case series have demonstrated the short-term efficacy and safety of STAR, although long-term outcomes remain unclear. Imaging techniques, such as electroanatomical mapping, contrast-enhanced magnetic resonance imaging and nuclear imaging, play a crucial role in treatment planning by identifying VT substrates and guiding target delineation. However, challenges persist owing to the complex anatomy and variability in target volume definitions. Advances in imaging and artificial intelligence are expected to improve the precision and efficacy of STAR. The exact mechanisms underlying the antiarrhythmic effects of STAR, including potential fibrosis and improvement in cardiac conduction, are still being explored. Despite its potential, STAR should be cautiously applied in prospective clinical trials, with a focus on optimizing dose delivery and understanding long-term outcomes. Collaborative efforts are necessary to standardize treatment strategies and enhance the quality of life for patients with refractory VT.

DOI： 10.1093/jrr/rrae090

Evaluation of 4D Flow MRI-Derived Relative Residence Time as a Marker for Cirrhosis Associated Portal Vein Thrombosis. Reviewed International journal Open Access

Ryota Hyodo, Yasuo Takehara, Yoji Ishizu, Kazuki Nishida, Takashi Mizuno, Kazushige Ichikawa, Ryota Horiguchi, Nobuhiko Kurata, Yasuhiro Ogura, Shinya Yokoyama, Shinji Naganawa, Ning Jin, Yoshito Ichiba

Journal of magnetic resonance imaging : JMRI Vol. 60 ( 6 ) page： 2592 - 2601 2024.12

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Portal vein thrombosis (PVT) is thought to arise from stagnant blood flow, yet conclusive evidence is lacking. Relative residence time (RRT) assessed using 4D Flow MRI may offer insight into portal flow stagnation. PURPOSE: To explore the relationship between RRT values and the presence of PVT in cirrhotic participants. STUDY TYPE: Prospective. POPULATION: Forty-eight participants with liver cirrhosis (27 males, median age 67 years [IQR: 57-73]) and 20 healthy control participants (12 males, median age 45 years [IQR: 40-54]). FIELD STRENGTH/SEQUENCE: 3 T/4D Flow MRI. ASSESSMENT: Laboratory (liver and kidney function test results and platelet count) and clinical data (presence of tumors and other imaging findings), and portal hemodynamics derived from 4D Flow MRI (spatiotemporally averaged RRT [RRT-mean], flow velocity, and flow rate) were analyzed. STATISTICAL TESTS: We used multivariable logistic regression, adjusted by selected covariates through the Lasso method, to explore whether RRT-mean is an independent risk factor for PVT. The area under the ROC curve (AUC) was also calculated to assess the model's discriminative ability. P < 0.05 indicated statistical significance. RESULTS: The liver cirrhosis group consisted of 16 participants with PVT and 32 without PVT. Higher RRT-mean values (odds ratio [OR] 11.4 [95% CI: 2.19, 118]) and lower platelet count (OR 0.98 per 1000 μL [95% CI: 0.96, 0.99]) were independent risk factors for PVT. The incorporation of RRT-mean (AUC, 0.77) alongside platelet count (AUC, 0.75) resulted in an AUC of 0.84. When including healthy control participants, RRT-mean had an adjusted OR of 12.4 and the AUC of the combined model (RRT-mean and platelet count) was 0.90. DATA CONCLUSION: Prolonged RRT values and low platelet count were significantly associated with the presence of PVT in cirrhotic participants. RRT values derived from 4D Flow MRI may have potential clinical relevance in the management of PVT. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

DOI： 10.1002/jmri.29357

Climate change and artificial intelligence in healthcare: Review and recommendations towards a sustainable future Reviewed Open Access

Daiju Ueda, Shannon L Walston, Shohei Fujita, Yasutaka Fushimi, Takahiro Tsuboyama, Koji Kamagata, Akira Yamada, Masahiro Yanagawa, Rintaro Ito, Noriyuki Fujima, Mariko Kawamura, Takeshi Nakaura, Yusuke Matsui, Fuminari Tatsugami, Tomoyuki Fujioka, Taiki Nozaki, Kenji Hirata, Shinji Naganawa

Diagnostic and Interventional Imaging Vol. 105 ( 11 ) page： 453 - 459 2024.11

Generative AI and large language models in nuclear medicine: current status and future prospects. Reviewed Open Access

Kenji Hirata, Yusuke Matsui, Akira Yamada, Tomoyuki Fujioka, Masahiro Yanagawa, Takeshi Nakaura, Rintaro Ito, Daiju Ueda, Shohei Fujita, Fuminari Tatsugami, Yasutaka Fushimi, Takahiro Tsuboyama, Koji Kamagata, Taiki Nozaki, Noriyuki Fujima, Mariko Kawamura, Shinji Naganawa

Annals of nuclear medicine Vol. 38 ( 11 ) page： 853 - 864 2024.11

Language：English Publishing type：Research paper (scientific journal)

This review explores the potential applications of Large Language Models (LLMs) in nuclear medicine, especially nuclear medicine examinations such as PET and SPECT, reviewing recent advancements in both fields. Despite the rapid adoption of LLMs in various medical specialties, their integration into nuclear medicine has not yet been sufficiently explored. We first discuss the latest developments in nuclear medicine, including new radiopharmaceuticals, imaging techniques, and clinical applications. We then analyze how LLMs are being utilized in radiology, particularly in report generation, image interpretation, and medical education. We highlight the potential of LLMs to enhance nuclear medicine practices, such as improving report structuring, assisting in diagnosis, and facilitating research. However, challenges remain, including the need for improved reliability, explainability, and bias reduction in LLMs. The review also addresses the ethical considerations and potential limitations of AI in healthcare. In conclusion, LLMs have significant potential to transform existing frameworks in nuclear medicine, making it a critical area for future research and development.

DOI： 10.1007/s12149-024-01981-x

The Evolution and Clinical Impact of Deep Learning Technologies in Breast MRI. Reviewed Open Access

Tomoyuki Fujioka, Shohei Fujita, Daiju Ueda, Rintaro Ito, Mariko Kawamura, Yasutaka Fushimi, Takahiro Tsuboyama, Masahiro Yanagawa, Akira Yamada, Fuminari Tatsugami, Koji Kamagata, Taiki Nozaki, Yusuke Matsui, Noriyuki Fujima, Kenji Hirata, Takeshi Nakaura, Ukihide Tateishi, Shinji Naganawa

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 2024.10

Language：English Publishing type：Research paper (scientific journal)

The integration of deep learning (DL) in breast MRI has revolutionized the field of medical imaging, notably enhancing diagnostic accuracy and efficiency. This review discusses the substantial influence of DL technologies across various facets of breast MRI, including image reconstruction, classification, object detection, segmentation, and prediction of clinical outcomes such as response to neoadjuvant chemotherapy and recurrence of breast cancer. Utilizing sophisticated models such as convolutional neural networks, recurrent neural networks, and generative adversarial networks, DL has improved image quality and precision, enabling more accurate differentiation between benign and malignant lesions and providing deeper insights into disease behavior and treatment responses. DL's predictive capabilities for patient-specific outcomes also suggest potential for more personalized treatment strategies. The advancements in DL are pioneering a new era in breast cancer diagnostics, promising more personalized and effective healthcare solutions. Nonetheless, the integration of this technology into clinical practice faces challenges, necessitating further research, validation, and development of legal and ethical frameworks to fully leverage its potential.

DOI： 10.2463/mrms.rev.2024-0056

Decreased diffusivity along the perivascular space and cerebral hemodynamic disturbance in adult moyamoya disease Reviewed

Shoko Hara, Junko Kikuta, Kaito Takabayashi, Koji Kamagata, Shihori Hayashi, Motoki Inaji, Yoji Tanaka, Masaaki Hori, Kenji Ishii, Tadashi Nariai, Toshiaki Taoka, Shinji Naganawa, Shigeki Aoki, Taketoshi Maehara

Journal of Cerebral Blood Flow & Metabolism Vol. 44 ( 10 ) page： 1787 - 1800 2024.10

Language：English Publishing type：Research paper (scientific journal) Publisher：SAGE Publications

Moyamoya disease (MMD) causes cerebral arterial stenosis and hemodynamic disturbance, the latter of which may disrupt glymphatic system activity, the waste clearance system. We evaluated 46 adult patients with MMD and 33 age- and sex-matched controls using diffusivity along the perivascular space (ALPS) measured with diffusion tensor imaging (ALPS index), which may partly reflect glymphatic system activity, and multishell diffusion MRI to generate freewater maps. Twenty-three patients were also evaluated via 15O-gas positron emission tomography (PET), and all patients underwent cognitive tests. Compared to controls, patients (38.4 (13.2) years old, 35 females) had lower ALPS indices in the left and right hemispheres (1.94 (0.27) vs. 1.65 (0.25) and 1.94 (0.22) vs. 1.65 (0.19), P < 0.001). While the right ALPS index showed no correlation, the left ALPS index was correlated with parenchymal freewater ( ρ = −0.47, P < 0.001); perfusion measured with PET (cerebral blood flow, ρ = 0.70, P < 0.001; mean transit time, ρ = −0.60, P = 0.003; and oxygen extraction fraction, ρ = −0.52, P = 0.003); and cognitive tests (trail making test part B for executive function; ρ = −0.37, P = 0.01). Adult patients with MMD may exhibit decreased glymphatic system activity, which is correlated with the degree of hemodynamic disturbance, increased interstitial freewater, and cognitive dysfunction, but further investigation is needed.

DOI： 10.1177/0271678X241245492

Other Link： https://journals.sagepub.com/doi/full-xml/10.1177/0271678X241245492

Comparing Lesion Conspicuity and ADC Reliability in High-resolution Diffusion-weighted Imaging of the Breast. Reviewed Open Access

Mami Iima, Rena Nakayama, Masako Kataoka, Martins Otikovs, Noam Nissan, Lucio Frydman, Yuta Urushibata, Maya Honda, Aika Okazawa, Hiroko Satake, Shinji Naganawa, Yuji Nakamoto

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 2024.9

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: This study investigated the breast lesion conspicuity and apparent diffusion coefficient (ADC) reliability for three different diffusion-weighted imaging (DWI) protocols: spatiotemporal encoding (SPEN), single-shot echo-planar imaging (SS-EPI), and readout segmentation of long variable echo-trains (RESOLVE). METHODS: Sixty-five women suspected of having breast tumors were included in this study, with 44 lesions (36 malignant, 8 benign) analyzed further. Breast MRI was performed on a 3 Tesla (3T) system (MAGNETOM Prisma, Siemens) equipped with a dedicated 18-channel breast array coil for a phantom and patients. Three DWI protocols-SPEN, SS-EPI, and RESOLVE-were used. SS-EPI was acquired with an in-plane resolution of 2 × 2 mm2, a slice thickness of 3 mm, and b-values of 0 and 1000 s/mm2. SPEN had a higher in-plane resolution of 1 × 1 mm2, a slice thickness of 1.5 mm, and b-values of 0, 850, and 1500 s/mm2. RESOLVE was acquired with an in-plane resolution of 1 × 1 mm2, a slice thickness of 1.5 mm, and b-values of 0 and 850 s/mm2. Lesion conspicuity and ADC values were evaluated. RESULTS: The average lesion conspicuity scores were significantly higher for RESOLVE (3.54 ± 0.65) than for SPEN (3.07 ± 0.91) or SS-EPI (2.48 ± 0.78) (P < 0.01). The SPEN score was significantly higher than the SS-EPI score (P < 0.01). Phantom measurements indicated marginally lower ADC values for SPEN compared to SS-EPI and RESOLVE across all concentrations. The results revealed that SPEN (b = 0, 850, 1500 sec/mm2) yielded significantly lower ADC values compared to SPEN (b = 0, 850 sec/mm2) in malignant lesions (P < 0.01), with no significant difference observed between SPEN (b = 0, 850 sec/mm2), SS-EPI, and RESOLVE. For benign lesions, no significant difference in ADC values was found between SPEN (b = 0, 850 sec/mm2), SPEN (b = 0, 850, 1500 sec/mm2), SS-EPI, and RESOLVE. CONCLUSION: RESOLVE provided the highest lesion conspicuity, and ADC values in breast lesions were not significantly different among sequences ranging b values 850-1000 sec/mm2. SPEN with higher b-values (0, 850, 1500 vs. 0, 850 sec/mm2) yielded significantly lower ADC values in malignant lesions, highlighting the importance of b-value selection in ADC quantification.

DOI： 10.2463/mrms.tn.2024-0089

Response to letter to the editor from Dr. Muhammed Said Beşler: 'the accuracy of large language models in RANZCR's clinical radiology exam sample questions'. Reviewed

Takeshi Nakaura, Shinji Naganawa

Japanese journal of radiology Vol. 42 ( 9 ) page： 1081 - 1082 2024.9

Imaging evaluation and volumetric measurement of the space surrounding the diploic veins. Reviewed Open Access

Rei Nakamichi, Toshiaki Taoka, Rintaro Ito, Tadao Yoshida, Michihiko Sone, Shinji Naganawa

Japanese journal of radiology Vol. 42 ( 9 ) page： 953 - 961 2024.9

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The diploic veins have been suggested to be involved in the excretion of cerebrospinal fluid and intracranial waste products; however, to date, there have been no reports evaluating the space surrounding the diploic veins. Therefore, we aimed to visualize the distribution of gadolinium-based contrast agent (GBCA) in the space surrounding the diploic veins and to evaluate the spatial characteristics. MATERIALS AND METHODS: Ninety-eight participants (aged 14-84 years) were scanned 4 h after intravenous GBCA injection at Nagoya University Hospital between April 2021 and December 2022. The volume of the space surrounding the diploic veins where the GBCA was distributed was measured using contrast-enhanced T1-weighted images with the application of three-axis motion-sensitized driven equilibrium. The parasagittal dura (PSD) volume adjacent to the superior sagittal sinus was also measured using the same images. Both volumes were corrected for intracranial volume. The correlation between age and the corrected volume was examined using Spearman's rank correlation coefficient; the relationship between the corrected volume and sex was assessed using the Mann-Whitney U test. RESULTS: A significant weak negative correlation was observed between the volume of the space surrounding the diploic veins and age (r = -0.330, p < 0.001). Furthermore, there was a significant weak positive correlation between the PSD volume and age (r = 0.385, p < 0.001). Both volumes were significantly greater in men than in women. There was no correlation between the volume of the space surrounding the diploic veins and the volume of the PSD. CONCLUSION: The volume of the space surrounding the diploic veins was measurable and, in contrast to the volume of the PSD, was greater in younger participants. This space may be related to intracranial excretory mechanisms and immune responses during youth, requiring further research.

DOI： 10.1007/s11604-024-01572-w

Overview of Target-Oriented Project Group United for Nippon (TOP GUN): fostering interdisciplinary collaboration among young researchers in radiology on timely topics. Reviewed Open Access

Koji Kamagata, Shinji Naganawa

Japanese journal of radiology Vol. 42 ( 9 ) page： 935 - 936 2024.9

Recent trends in AI applications for pelvic MRI: a comprehensive review Reviewed

Takahiro Tsuboyama, Masahiro Yanagawa, Tomoyuki Fujioka, Shohei Fujita, Daiju Ueda, Rintaro Ito, Akira Yamada, Yasutaka Fushimi, Fuminari Tatsugami, Takeshi Nakaura, Taiki Nozaki, Koji Kamagata, Yusuke Matsui, Kenji Hirata, Noriyuki Fujima, Mariko Kawamura, Shinji Naganawa

La radiologia medica Vol. 129 ( 9 ) page： 1369 - 1381 2024.9

The impact of large language models on radiology: a guide for radiologists on the latest innovations in AI. Reviewed Open Access

Takeshi Nakaura, Rintaro Ito, Daiju Ueda, Taiki Nozaki, Yasutaka Fushimi, Yusuke Matsui, Masahiro Yanagawa, Akira Yamada, Takahiro Tsuboyama, Noriyuki Fujima, Fuminari Tatsugami, Kenji Hirata, Shohei Fujita, Koji Kamagata, Tomoyuki Fujioka, Mariko Kawamura, Shinji Naganawa

Japanese journal of radiology Vol. 42 ( 7 ) page： 685 - 696 2024.7

Language：English Publishing type：Research paper (scientific journal)

The advent of Deep Learning (DL) has significantly propelled the field of diagnostic radiology forward by enhancing image analysis and interpretation. The introduction of the Transformer architecture, followed by the development of Large Language Models (LLMs), has further revolutionized this domain. LLMs now possess the potential to automate and refine the radiology workflow, extending from report generation to assistance in diagnostics and patient care. The integration of multimodal technology with LLMs could potentially leapfrog these applications to unprecedented levels.However, LLMs come with unresolved challenges such as information hallucinations and biases, which can affect clinical reliability. Despite these issues, the legislative and guideline frameworks have yet to catch up with technological advancements. Radiologists must acquire a thorough understanding of these technologies to leverage LLMs' potential to the fullest while maintaining medical safety and ethics. This review aims to aid in that endeavor.

DOI： 10.1007/s11604-024-01552-0

Evaluation of alterations in interstitial fluid dynamics in cases of whole-brain radiation using the diffusion-weighted image analysis along the perivascular space method. Reviewed International journal Open Access

Toshiaki Taoka, Rintaro Ito, Rei Nakamichi, Toshiki Nakane, Mariko Kawamura, Shunichi Ishihara, Kazushige Ichikawa, Hisashi Kawai, Shinji Naganawa

NMR in biomedicine Vol. 37 ( 7 ) page： e5030 2024.7

Language：English Publishing type：Research paper (scientific journal)

In the current study, we assessed changes in interstitial fluid dynamics resulting after whole-brain radiotherapy using the diffusion-weighted image analysis along the perivascular space (DWI-ALPS) method, which is a simplified variation of the diffusion tensor image ALPS (DTI-ALPS) method using diffusion-weighted imaging (DWI) with orthogonal motion-probing gradients (MPGs). This retrospective study included 47 image sets from 22 patients who underwent whole-brain radiotherapy for brain tumors. The data for the normal control group comprised 105 image sets from 105 participants with no pathological changes. DWI was performed with the three MPGs applied in an orthogonal direction to the imaging plane, and apparent diffusion coefficient images for the x-, y-, and z-axes were retrospectively generated. The ALPS index was calculated to quantify interstitial fluid dynamics. The independent t-test was used to compare the ALPS index between normal controls and patients who underwent whole-brain radiotherapy. Patients were compared in all age groups and individual age groups (20-39, 40-59, and 60-84 years). We also examined the correlation between biologically equivalent doses (BEDs) and the ALPS index, as well as the correlation between white matter hyperintensity and the ALPS index. In the comparison of all age groups, the ALPS index was significantly lower (p < 0.001) in the postradiation group (1.32 ± 0.16) than in the control group (1.44 ± 0.17), suggesting that interstitial fluid dynamics were altered in patients following whole-brain radiotherapy. Significant age group differences were found (40-59 years: p < 0.01; 60-84 years: p < 0.001), along with a weak negative correlation between BEDs (r = -0.19) and significant correlations between white matter hyperintensity and the ALPS index (r = -0.46 for periventricular white matter, r = -0.38 for deep white matter). It was concluded that the ALPS method using DWI with orthogonal MPGs suggest alteration in interstitial fluid dynamics in patients after whole-brain radiotherapy. Further systematic prospective studies are required to investigate their association with cognitive symptoms.

DOI： 10.1002/nbm.5030

Palliative radiotherapy for painful non-bone lesions in patients with advanced cancer: a single center retrospective study Reviewed Open Access

Yurika Shindo, Yutaro Koide, Naoya Nagai, Tomoki Kitagawa, Takahiro Aoyama, Hidetoshi Shimizu, Shingo Hashimoto, Hiroyuki Tachibana, Takeshi Kodaira, Shunichi Ishihara, Shinji Naganawa

JAPANESE JOURNAL OF RADIOLOGY Vol. 42 ( 6 ) page： 656 - 661 2024.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

Abstract

Purpose

This retrospective study aimed to assess the efficacy and safety of palliative radiotherapy for painful non-bone lesions in patients with advanced cancer.

Materials and methods

We enrolled patients with painful non-bone lesions who underwent conventional palliative radiotherapy between September 2018 and September 2022. The treatment targets included primary tumor lesions, lymph node metastases, non-bone hematogenous metastases, and other lesions. The primary endpoint was the overall pain response rate in evaluable patients, determined based on the International Consensus Pain Response Endpoint criteria. The secondary endpoints included overall survival, pain recurrence, and adverse events.

Results

Of the 420 screened patients, 142 received palliative radiotherapy for painful non-bone lesions, and 112 were evaluable. A pain response was achieved in 67 patients (60%) of the 112 evaluable patients within a median of 1.2 months. Among these patients, 25 exhibited complete response, 42 partial response, 18 indeterminate response, and 27 pain progression. The median survival time was 5.5 months, recorded at a median follow-up of 6.0 months, during which 67 patients died. Multivariate analysis identified poor performance status scores of 2–4, opioid use, and re-irradiation as independent factors associated with a reduced likelihood of achieving a pain response. Pain recurrence occurred in 18 patients over a median of 4.1 months. Seventeen patients had grade 1–2 adverse events, while none experienced grade 3 or higher toxicity.

Conclusion

Palliative radiotherapy can potentially be a safe and well-tolerated modality for managing painful non-bone lesions, with a low rate of adverse events.

DOI： 10.1007/s11604-024-01536-0

Other Link： https://link.springer.com/article/10.1007/s11604-024-01536-0/fulltext.html

Direct Visualization of Tracer Permeation into the Endolymph in Human Patients Using MR Imaging. Reviewed Open Access

Shinji Naganawa, Rintaro Ito, Mariko Kawamura, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 24 ( 2 ) page： 253 - 261 2024.4

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The endolymph of the inner ear, vital for balance and hearing, has long been considered impermeable to intravenously administered gadolinium-based contrast agents (GBCAs) due to the tight blood-endolymph barrier. However, anecdotal observations suggested potential GBCA entry in delayed heavily T2-weighted 3D-real inversion recovery (IR) MRI scans. This study systematically investigated GBCA distribution in the endolymph using this 3D-real IR sequence. METHODS: Forty-one patients suspected of endolymphatic hydrops (EHs) underwent pre-contrast, 4-h, and 24-h post-contrast 3D-real IR imaging. Signal intensity in cerebrospinal fluid (CSF), perilymph, and endolymph was measured and analyzed for temporal dynamics of GBCA uptake, correlations between compartments, and the influence of age and presence of EH. RESULTS: Endolymph showed a delayed peak GBCA uptake at 24h, contrasting with peaks in perilymph and CSF at 4h. Weak to moderate positive correlations between endolymph and CSF contrast effect were observed at both 4 (r = 0.483) and 24h (r = 0.585), suggesting possible inter-compartmental interactions. Neither the presence of EH nor age significantly influenced endolymph enhancement. However, both perilymph and CSF contrast effects significantly correlated with age at both time points. CONCLUSION: This study provides the first in vivo systematic confirmation of GBCA entering the endolymph following intravenous administration. Notably, endolymph uptake peaked at 24h, significantly later than perilymph and CSF. The lack of a link between endolymph contrast and both perilymph and age suggests distinct uptake mechanisms. These findings shed light on inner ear fluid dynamics and their potential implications in Ménière's disease and other inner ear disorders.

DOI： 10.2463/mrms.mp.2024-0011

Diffusion Tensor Image Analysis ALong the Perivascular Space (DTI-ALPS): Revisiting the Meaning and Significance of the Method. Reviewed Open Access

Toshiaki Taoka, Rintaro Ito, Rei Nakamichi, Toshiki Nakane, Hisashi Kawai, Shinji Naganawa

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 23 ( 3 ) page： 268 - 290 2024.4

Language：English Publishing type：Research paper (scientific journal)

More than 5 years have passed since the Diffusion Tensor Image Analysis ALong the Perivascular Space (DTI-ALPS) method was proposed with the intention of evaluating the glymphatic system. This method is handy due to its noninvasiveness, provision of a simple index in a straightforward formula, and the possibility of retrospective analysis. Therefore, the ALPS method was adopted to evaluate the glymphatic system for many disorders in many studies. The purpose of this review is to look back and discuss the ALPS method at this moment.The ALPS-index was found to be an indicator of a number of conditions related to the glymphatic system. Thus, although this was expected in the original report, the results of the ALPS method are often interpreted as uniquely corresponding to the function of the glymphatic system. However, a number of subsequent studies have pointed out the problems on the data interpretation. As they rightly point out, a higher ALPS-index indicates predominant Brownian motion of water molecules in the radial direction at the lateral ventricular body level, no more and no less. Fortunately, the term "ALPS-index" has become common and is now known as a common term by many researchers. Therefore, the ALPS-index should simply be expressed as high or low, and whether it reflects a glymphatic system is better to be discussed carefully. In other words, when a decreased ALPS-index is observed, it should be expressed as "decreased ALPS-index" and not directly as "glymphatic dysfunction". Recently, various methods have been proposed to evaluate the glymphatic system. It has become clear that these methods also do not seem to reflect the entirety of the extremely complex glymphatic system. This means that it would be desirable to use various methods in combination to evaluate the glymphatic system in a comprehensive manner.

DOI： 10.2463/mrms.rev.2023-0175

Assessing interstitial fluid dynamics in type 2 diabetes mellitus and prediabetes cases through diffusion tensor imaging analysis along the perivascular space Reviewed Open Access

Rukeye Tuerxun, Koji Kamagata, Yuya Saito, Christina Andica, Kaito Takabayashi, Wataru Uchida, Seina Yoshida, Junko Kikuta, Hiroki Tabata, Hitoshi Naito, Yuki Someya, Hideyoshi Kaga, Mari Miyata, Toshiaki Akashi, Akihiko Wada, Toshiaki Taoka, Shinji Naganawa, Yoshifumi Tamura, Hirotaka Watada, Ryuzo Kawamori, Shigeki Aoki

Frontiers in Aging Neuroscience Vol. 16 page： 1362457 2024.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Frontiers Media SA

Background and purpose

Glymphatic system in type 2 diabetes mellitus (T2DM) but not in the prodrome, prediabetes (Pre-DM) was investigated using diffusion tensor image analysis along the perivascular space (DTI-ALPS). Association between glymphatic system and insulin resistance of prominent characteristic in T2DM and Pre-DM between is yet elucidated. Therefore, this study delves into the interstitial fluid dynamics using the DTI-ALPS in both Pre-DM and T2DM and association with insulin resistance.

Materials and methods

In our cross-sectional study, we assessed 70 elderly individuals from the Bunkyo Health Study, which included 22 with Pre-DM, 18 with T2DM, and 33 healthy controls with normal glucose metabolism (NGM). We utilized the general linear model (GLM) to evaluate the ALPS index based on DTI-ALPS across these groups, considering variables like sex, age, intracranial volume, years of education, anamnesis of hypertension and hyperlipidemia, and the total Fazekas scale. Furthermore, we have explored the relationship between the ALPS index and insulin resistance, as measured by the homeostasis model assessment of insulin resistance (HOMA-IR) using GLM and the same set of covariates.

Results

In the T2DM group, the ALPS index demonstrated a reduction compared with the NGM group [family-wise error (FWE)-corrected p &lt; 0.001; Cohen's d = −1.32]. Similarly, the Pre-DM group had a lower ALPS index than the NGM group (FWE-corrected p &lt; 0.001; Cohen's d = −1.04). However, there was no significant disparity between the T2DM and Pre-DM groups (FWE-corrected p = 1.00; Cohen's d = −0.63). A negative correlation was observed between the ALPS index and HOMA-IR in the combined T2DM and Pre-DM groups (partial correlation coefficient r = −0.35, p &lt; 0.005).

Conclusion

The ALPS index significantly decreased in both the pre-DM and T2DM groups and showed a correlated with insulin resistance. This indicated that changes in interstitial fluid dynamics are associated with insulin resistance.

DOI： 10.3389/fnagi.2024.1362457

Current Understanding of the Anatomy, Physiology, and Magnetic Resonance Imaging of Neurofluids: Update From the 2022 "ISMRM Imaging Neurofluids Study group" Workshop in Rome. Reviewed International journal

Nivedita Agarwal, Laura D Lewis, Lydiane Hirschler, Leonardo Rivera Rivera, Shinji Naganawa, Swati Rane Levendovszky, Geir Ringstad, Marijan Klarica, Joanna Wardlaw, Costantino Iadecola, Cheryl Hawkes, Roxana Octavia Carare, Jack Wells, Erik N T P Bakker, Vartan Kurtcuoglu, Lynne Bilston, Maiken Nedergaard, Yuki Mori, Marcus Stoodley, Noam Alperin, Mony de Leon, Matthias J P van Osch

JOURNAL OF MAGNETIC RESONANCE IMAGING Vol. 59 ( 2 ) page： 431 - 449 2024.2

Language：English Publishing type：Research paper (scientific journal)

Neurofluids is a term introduced to define all fluids in the brain and spine such as blood, cerebrospinal fluid, and interstitial fluid. Neuroscientists in the past millennium have steadily identified the several different fluid environments in the brain and spine that interact in a synchronized harmonious manner to assure a healthy microenvironment required for optimal neuroglial function. Neuroanatomists and biochemists have provided an incredible wealth of evidence revealing the anatomy of perivascular spaces, meninges and glia and their role in drainage of neuronal waste products. Human studies have been limited due to the restricted availability of noninvasive imaging modalities that can provide a high spatiotemporal depiction of the brain neurofluids. Therefore, animal studies have been key in advancing our knowledge of the temporal and spatial dynamics of fluids, for example, by injecting tracers with different molecular weights. Such studies have sparked interest to identify possible disruptions to neurofluids dynamics in human diseases such as small vessel disease, cerebral amyloid angiopathy, and dementia. However, key differences between rodent and human physiology should be considered when extrapolating these findings to understand the human brain. An increasing armamentarium of noninvasive MRI techniques is being built to identify markers of altered drainage pathways. During the three-day workshop organized by the International Society of Magnetic Resonance in Medicine that was held in Rome in September 2022, several of these concepts were discussed by a distinguished international faculty to lay the basis of what is known and where we still lack evidence. We envision that in the next decade, MRI will allow imaging of the physiology of neurofluid dynamics and drainage pathways in the human brain to identify true pathological processes underlying disease and to discover new avenues for early diagnoses and treatments including drug delivery. Evidence level: 1 Technical Efficacy: Stage 3.

DOI： 10.1002/jmri.28759

Revolutionizing radiation therapy: the role of AI in clinical practice Reviewed

Mariko Kawamura, Takeshi Kamomae, Masahiro Yanagawa, Koji Kamagata, Shohei Fujita, Daiju Ueda, Yusuke Matsui, Yasutaka Fushimi, Tomoyuki Fujioka, Taiki Nozaki, Akira Yamada, Kenji Hirata, Rintaro Ito, Noriyuki Fujima, Fuminari Tatsugami, Takeshi Nakaura, Takahiro Tsuboyama, Shinji Naganawa

Journal of Radiation Research Vol. 65 ( 1 ) page： 1 - 9 2024.1

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：Oxford University Press (OUP)

Abstract

This review provides an overview of the application of artificial intelligence (AI) in radiation therapy (RT) from a radiation oncologist’s perspective. Over the years, advances in diagnostic imaging have significantly improved the efficiency and effectiveness of radiotherapy. The introduction of AI has further optimized the segmentation of tumors and organs at risk, thereby saving considerable time for radiation oncologists. AI has also been utilized in treatment planning and optimization, reducing the planning time from several days to minutes or even seconds. Knowledge-based treatment planning and deep learning techniques have been employed to produce treatment plans comparable to those generated by humans. Additionally, AI has potential applications in quality control and assurance of treatment plans, optimization of image-guided RT and monitoring of mobile tumors during treatment. Prognostic evaluation and prediction using AI have been increasingly explored, with radiomics being a prominent area of research. The future of AI in radiation oncology offers the potential to establish treatment standardization by minimizing inter-observer differences in segmentation and improving dose adequacy evaluation. RT standardization through AI may have global implications, providing world-standard treatment even in resource-limited settings. However, there are challenges in accumulating big data, including patient background information and correlating treatment plans with disease outcomes. Although challenges remain, ongoing research and the integration of AI technology hold promise for further advancements in radiation oncology.

DOI： 10.1093/jrr/rrad090

Fairness of artificial intelligence in healthcare: review and recommendations Reviewed

Daiju Ueda, Taichi Kakinuma, Shohei Fujita, Koji Kamagata, Yasutaka Fushimi, Rintaro Ito, Yusuke Matsui, Taiki Nozaki, Takeshi Nakaura, Noriyuki Fujima, Fuminari Tatsugami, Masahiro Yanagawa, Kenji Hirata, Akira Yamada, Takahiro Tsuboyama, Mariko Kawamura, Tomoyuki Fujioka, Shinji Naganawa

Japanese Journal of Radiology Vol. 42 ( 1 ) page： 3 - 15 2024.1

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

In this review, we address the issue of fairness in the clinical integration of artificial intelligence (AI) in the medical field. As the clinical adoption of deep learning algorithms, a subfield of AI, progresses, concerns have arisen regarding the impact of AI biases and discrimination on patient health. This review aims to provide a comprehensive overview of concerns associated with AI fairness; discuss strategies to mitigate AI biases; and emphasize the need for cooperation among physicians, AI researchers, AI developers, policymakers, and patients to ensure equitable AI integration. First, we define and introduce the concept of fairness in AI applications in healthcare and radiology, emphasizing the benefits and challenges of incorporating AI into clinical practice. Next, we delve into concerns regarding fairness in healthcare, addressing the various causes of biases in AI and potential concerns such as misdiagnosis, unequal access to treatment, and ethical considerations. We then outline strategies for addressing fairness, such as the importance of diverse and representative data and algorithm audits. Additionally, we discuss ethical and legal considerations such as data privacy, responsibility, accountability, transparency, and explainability in AI. Finally, we present the Fairness of Artificial Intelligence Recommendations in healthcare (FAIR) statement to offer best practices. Through these efforts, we aim to provide a foundation for discussing the responsible and equitable implementation and deployment of AI in healthcare.

DOI： 10.1007/s11604-023-01474-3

The Glymphatic System in Humans: Investigations With Magnetic Resonance Imaging. Reviewed International journal

Shinji Naganawa, Toshiaki Taoka, Rintaro Ito, Mariko Kawamura

Investigative radiology Vol. 59 ( 1 ) page： 1 - 12 2024.1

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

The concept of the glymphatic system was proposed more than a decade ago as a mechanism for interstitial fluid flow and waste removal in the central nervous system. The function of the glymphatic system has been shown to be particularly activated during sleep. Dysfunction of the glymphatic system has been implicated in several neurodegenerative diseases. Noninvasive in vivo imaging of the glymphatic system is expected to be useful in elucidating the pathophysiology of these diseases. Currently, magnetic resonance imaging is the most commonly used technique to evaluate the glymphatic system in humans, and a large number of studies have been reported. This review provides a comprehensive overview of investigations of the human glymphatic system function using magnetic resonance imaging. The studies can be divided into 3 categories, including imaging without gadolinium-based contrast agents (GBCAs), imaging with intrathecal administration of GBCAs, and imaging with intravenous administration of GBCAs. The purpose of these studies has been to examine not only the interstitial fluid movement in the brain parenchyma, but also the fluid dynamics in the perivascular and subarachnoid spaces, as well as the parasagittal dura and meningeal lymphatics. Recent research has even extended to include the glymphatic system of the eye and the inner ear. This review serves as an important update and a useful guide for future research directions.

DOI： 10.1097/RLI.0000000000000969

Glymphatic System Dysfunction in Myelin Oligodendrocyte Glycoprotein Immunoglobulin G Antibody-Associated Disorders: Association with Clinical Disability. Reviewed International journal

Akifumi Hagiwara, Yuji Tomizawa, Yasunobu Hoshino, Kazumasa Yokoyama, Koji Kamagata, Towa Sekine, Kaito Takabayashi, Moto Nakaya, Tomoko Maekawa, Toshiaki Akashi, Akihiko Wada, Toshiaki Taoka, Shinji Naganawa, Nobutaka Hattori, Shigeki Aoki

AJNR. American journal of neuroradiology Vol. 45 ( 1 ) page： 66 - 71 2024.1

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND AND PURPOSE: Impaired glymphatic function has been suggested to be implicated in the pathophysiology of MS and aquaporin-4 immunoglobulin G-positive neuromyelitis optica spectrum disorder. This study aimed to investigate the interstitial fluid dynamics in the brain in patients with myelin oligodendrocyte glycoprotein antibody disorders (MOGAD), another demyelinating disorder, using a noninvasive imaging technique called the diffusivity along the perivascular space (ALPS) index. MATERIALS AND METHODS: A prospective study was conducted on 16 patients with MOGAD in remission and 22 age- and sex-matched healthy control subjects. MR imaging was performed using a 3T scanner, and the ALPS index was calculated using diffusion MR imaging data with a b-value of 1000 s/mm2. The ALPS index and gray matter volumes were compared between the 2 groups, and these parameters were correlated with the Expanded Disability Status Scale. RESULTS: The mean ALPS index of patients with MOGAD was significantly lower than that of healthy controls (Cohen d = 0.93, false discovery rate-corrected P = .02). The lower mean ALPS index was significantly associated with a worse Expanded Disability Status Scale score (Spearman ρ = -0.51; 95% CI, -0.85 to -0.02; P = .03). However, cortical volume and deep gray matter volume were not significantly different between the 2 groups, and they were not correlated with the Expanded Disability Status Scale. CONCLUSIONS: This study suggests that patients with MOGAD may have impaired glymphatic function, as measured by the ALPS index, which is associated with patient disability. Further study is warranted with a larger sample size.

DOI： 10.3174/ajnr.A8066

Association between the Putative Meningeal Lymphatics at the Posterior Wall of the Sigmoid Sinus and Delayed Contrast-agent Elimination from the Cerebrospinal Fluid. Reviewed Open Access

Shinji Naganawa, Rintaro Ito, Mariko Kawamura, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 23 ( 1 ) page： 80 - 91 2024

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: To investigate the characteristics of the putative meningeal lymphatics located at the posterior wall of the sigmoid sinus (PML-PSS) in human subjects imaged before and after intravenous administration (IV) of a gadolinium-based contrast agent (GBCA). The appearance of the PML-PSS and the enhancement of the perivascular space of the basal ganglia (PVS-BG) were analyzed for an association with gender, age, and clearance of the GBCA from the cerebrospinal fluid (CSF). METHODS: Forty-two patients with suspected endolymphatic hydrops were included. Heavily T2-weighted 3D-fluid attenuated inversion recovery (hT2w-3D-FLAIR) and 3D-real inversion recovery (IR) images were obtained at pre-administration, immediately post-administration, and at 4 and 24 hours after IV-GBCA. The appearance of the PML-PSS and the presence of enhancement in the PVS-BG were analyzed for a relationship with age, gender, contrast enhancement of the CSF at 4 hours after IV-GBCA, and the washout ratio of the GBCA in the CSF from 4 to 24 hours after IV-GBCA. RESULTS: The PML-PSS and PVS-BG were seen in 23 of 42 and 21 of 42 cases, respectively, at 4 hours after IV-GBCA. In all PML-PSS positive cases, hT2w-3D-FLAIR signal enhancement was highest at 4 hours after IV-GBCA. A multivariate analysis between gender, age, CSF signal elevation at 4 hours, and washout ratio indicated that only the washout ratio was independently associated with the enhancement of the PML-PSS or PVS-BG. The odds ratios (95% CIs; P value) were 4.09 × 10-5 (2.39 × 10-8 - 0.07; 0.0078) for the PML-PSS and 1.7 × 10-4 (1.66 × 10-7 - 0.174; 0.014) for the PVS-BG. CONCLUSION: The PML-PSS had the highest signal enhancement at 4 hours after IV-GBCA. When the PML-PSS was seen, there was also often enhancement of the PVS-BG at 4 hours after IV-GBCA. Both observed enhancements were associated with delayed GBCA excretion from the CSF.

DOI： 10.2463/mrms.mp.2022-0110

Assessing the Real-World, Long-Term Impact of Lemborexant on Sleep Quality in a Home-Based Clinical Study. Reviewed International journal Open Access

Seiko Miyata, Kunihiro Iwamoto, Ippei Okada, Akihiro Fujimoto, Yuki Kogo, Daisuke Mori, Manabu Amano, Nao Matsuyama, Kazuki Nishida, Masahiko Ando, Toshiaki Taoka, Shinji Naganawa, Norio Ozaki

Nature and science of sleep Vol. 16 page： 291 - 303 2024

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Both subjective and objective evaluations are essential for the treatment of insomnia. Lemborexant has been shown to be effective in the long-term based solely on a subjective basis, and no long-term objective measures have been evaluated under natural sleep conditions. Small, lightweight sleep electroencephalogram (EEG) monitor was used, instead of polysomnography, to objectively evaluate sleep at home 4 and 12 weeks after lemborexant treatment. PATIENTS AND METHODS: Adults and elderly subjects with insomnia disorder, per the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, were enrolled in this open-label, single-arm, single-center trial. Objective and subjective measures of sleep were prospectively assessed. Sleep disturbance, excessive sleepiness, and depressive symptoms were assessed using questionnaires. RESULTS: A total of 45 subjects were screened, of which 33 were enrolled. Paired t-tests were conducted to evaluate changes in sleep variables and compared with the baseline; subjects showed significant improvements in objective sleep efficiency (SE) and subjective sleep parameters at weeks 4 and 12 following treatment with lemborexant. When baseline values were taken into account, a repeated-multivariate analysis of variance (MANOVA) revealed statistically significant changes in the objective measures. Sleep disturbance, excessive sleepiness, and depressive symptoms improved after three months of lemborexant treatment. CONCLUSION: Furthermore, lemborexant therapy improved nocturnal sleep, when measured objectively using sleep EEG monitoring at home, and improved daytime sleepiness and depressive symptoms in older adults with insomnia disorder.

DOI： 10.2147/NSS.S448871

Measurement of solid size in early-stage lung adenocarcinoma by virtual 3D thin-section CT applied artificial intelligence. Reviewed International journal

Shingo Iwano, Shinichiro Kamiya, Rintaro Ito, Akira Kudo, Yoshiro Kitamura, Keigo Nakamura, Shinji Naganawa

Scientific reports Vol. 13 ( 1 ) page： 21709 - 21709 2023.12

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

An artificial intelligence (AI) system that reconstructs virtual 3D thin-section CT (TSCT) images from conventional CT images by applying deep learning was developed. The aim of this study was to investigate whether virtual and real TSCT could measure the solid size of early-stage lung adenocarcinoma. The pair of original thin-CT and simulated thick-CT from the training data with TSCT images (thickness, 0.5-1.0 mm) of 2700 pulmonary nodules were used to train the thin-CT generator in the generative adversarial network (GAN) framework and develop a virtual TSCT AI system. For validation, CT images of 93 stage 0-I lung adenocarcinomas were collected, and virtual TSCTs were reconstructed from conventional 5-mm thick-CT images using the AI system. Two radiologists measured and compared the solid size of tumors on conventional CT and virtual and real TSCT. The agreement between the two observers showed an almost perfect agreement on the virtual TSCT for solid size measurements (intraclass correlation coefficient = 0.967, P < 0.001, respectively). The virtual TSCT had a significantly stronger correlation than that of conventional CT (P = 0.003 and P = 0.001, respectively). The degree of agreement between the clinical T stage determined by virtual TSCT and the clinical T stage determined by real TSCT was excellent in both observers (k = 0.882 and k = 0.881, respectively). The AI system developed in this study was able to measure the solid size of early-stage lung adenocarcinoma on virtual TSCT as well as on real TSCT.

DOI： 10.1038/s41598-023-48755-5

Recent advances in artificial intelligence for cardiac CT: Enhancing diagnosis and prognosis prediction Reviewed

第1章　画像診断機器　【基調論文】最新医療機器の現況と将来的方向性 2024年　最新医療機器の現状と展望 CTやMRIなどの画像診断装置の技術的到達点への評価と課題 Reviewed

長縄慎二

月間新医療データブック・シリーズ　医療機器システム白書 2024 page： 8 - 11 2023.12

公益社団法人愛知県医師会「現代医学」誌70巻号の特集テーマ「がん検診」座談会 Invited Reviewed

長縄慎二

現代醫学 Vol. 70 ( 2 ) page： 1 - 13 2023.12

Fuminari Tatsugami, Takeshi Nakaura, Masahiro Yanagawa, Shohei Fujita, Koji Kamagata, Rintaro Ito, Mariko Kawamura, Yasutaka Fushimi, Daiju Ueda, Yusuke Matsui, Akira Yamada, Noriyuki Fujima, Tomoyuki Fujioka, Taiki Nozaki, Takahiro Tsuboyama, Kenji Hirata, Shinji Naganawa

Diagnostic and Interventional Imaging Vol. 104 ( 11 ) page： 521 - 528 2023.11

＜Editors' Choice＞ Pattern of THK 5351 retention in normal aging involves core regions of resting state networks associated with higher cognitive function. Reviewed

Yusuke Yoshida, Takamasa Yokoi, Kazuhiro Hara, Hirohisa Watanabe, Hiroshi Yamaguchi, Epifanio Bagarinao, Michihito Masuda, Toshiyasu Kato, Aya Ogura, Reiko Ohdake, Kazuya Kawabata, Masahisa Katsuno, Katsuhiko Kato, Shinji Naganawa, Nobuyuki Okamura, Kazuhiko Yanai, Gen Sobue

Nagoya journal of medical science Vol. 85 ( 4 ) page： 758 - 771 2023.11

Language：English Publishing type：Research paper (scientific journal)

We aimed to elucidate the distribution pattern of the positron emission tomography probe [18F]THK 5351, a marker for astrogliosis and tau accumulation, in healthy aging. We also assessed the relationship between THK5351 retention and resting state networks. We enrolled 62 healthy participants in this study. All participants underwent magnetic resonance imaging/positron emission tomography scanning consisting of T1-weighted images, resting state functional magnetic resonance imaging, Pittsburgh Compound-B and THK positron emission tomography. The preprocessed THK images were entered into a scaled subprofile modeling/principal component analysis to extract THK distribution patterns. Using the most significant THK pattern, we generated regions of interest, and performed seed-based functional connectivity analyses. We also evaluated the functional connectivity overlap ratio to identify regions with high between-network connectivity. The most significant THK distributions were observed in the medial prefrontal cortex and bilateral putamen. The seed regions of interest in the medial prefrontal cortex had a functional connectivity map that significantly overlapped with regions of the dorsal default mode network. The seed regions of interest in the putamen showed strong overlap with the basal ganglia and anterior salience networks. The functional connectivity overlap ratio also showed that three peak regions had the characteristics of connector hubs. We have identified an age-related spatial distribution of THK in the medial prefrontal cortex and basal ganglia in normal aging. Interestingly, the distribution's peaks are located in regions of connector hubs that are strongly connected to large-scale resting state networks associated with higher cognitive function.

DOI： 10.18999/nagjms.85.4.758

From FDG and beyond: the evolving potential of nuclear medicine. Reviewed

Kenji Hirata, Koji Kamagata, Daiju Ueda, Masahiro Yanagawa, Mariko Kawamura, Takeshi Nakaura, Rintaro Ito, Fuminari Tatsugami, Yusuke Matsui, Akira Yamada, Yasutaka Fushimi, Taiki Nozaki, Shohei Fujita, Tomoyuki Fujioka, Takahiro Tsuboyama, Noriyuki Fujima, Shinji Naganawa

Annals of nuclear medicine Vol. 37 ( 11 ) page： 583 - 595 2023.11

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

The radiopharmaceutical 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) has been dominantly used in positron emission tomography (PET) scans for over 20 years, and due to its vast utility its applications have expanded and are continuing to expand into oncology, neurology, cardiology, and infectious/inflammatory diseases. More recently, the addition of artificial intelligence (AI) has enhanced nuclear medicine diagnosis and imaging with FDG-PET, and new radiopharmaceuticals such as prostate-specific membrane antigen (PSMA) and fibroblast activation protein inhibitor (FAPI) have emerged. Nuclear medicine therapy using agents such as [177Lu]-dotatate surpasses conventional treatments in terms of efficacy and side effects. This article reviews recently established evidence of FDG and non-FDG drugs and anticipates the future trajectory of nuclear medicine.

DOI： 10.1007/s12149-023-01865-6

Multisite harmonization of diffusion tensor image analysis along the perivascular space using the COMBined Association Test. Reviewed

Diffusivity Along the Perivascular Space is Decreased and Related to Hypoperfusion in Adult Moyamoya disease Reviewed

in press (https://www.researchsquare.com/article/rs-3411760/v1) 2023.10

Yuya Saito, Koji Kamagata, Christina Andica, Toshiaki Taoka, Rukeye Tuerxun, Wataru Uchida, Kaito Takabayashi, Mana Owaki, Seina Yoshida, Keigo Yamazaki, Shinji Naganawa, Shigeki Aoki

Japanese journal of radiology Vol. 41 ( 10 ) page： 1072 - 1083 2023.10

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: This multisite study aimed to use the COMBined Association Test (COMBAT), a harmonization technique that uses regression of covariates with an empirical Bayesian framework, to harmonize diffusion tensor image analysis along the perivascular space (DTI-ALPS) variations caused by scanner, site, and protocol differences. MATERIALS AND METHODS: This study included multisite diffusion magnetic resonance imaging (dMRI) data of 45 patients with Alzheimer's disease (AD) and 82 cognitively normal (CN) participants from the AD neuroimaging initiative database. The dMRI data were obtained with two b values (0 and 1000 s/mm2) from 27 institutions and three different 3-Tesla MRI scanners (two vendors). The ALPS index was calculated from multisite dMRI data, and COMBAT was used to harmonize the factors causing site variations. Welch's t test was used, Cohen's d was calculated to compare the difference in the ALPS index between AD and CN before and after harmonization, and Pearson's correlation coefficient was calculated to assess the relationships between the ALPS index and the cognitive score, [18F] fluorodeoxyglucose (FDG)-positron emission tomography (PET), and [18F] florbetapir (AV45)-PET standardized uptake value ratios (SUVRs). RESULTS: COMBAT harmonized scanner differences and increased Cohen's d of the left and right ALPS indexes between AD and CN from 0.288 to 0.438 and 0.328 to 0.480, respectively. The ALPS indexes were significantly different between AD and CN after harmonization (P < 0.05) but not before it. Moreover, Pearson's correlation coefficients between the ALPS index and cognitive score, FDG-PET, and AV45-PET SUVRs were higher after harmonization than before it. CONCLUSION: This study demonstrates the application of COMBAT harmonization to eliminate between-scanner, site, and protocol variations in the ALPS index calculated from DTI-ALPS using dMRI and possibly facilitate the use of the ALPS index in multi-center studies.

DOI： 10.1007/s11604-023-01432-z

New trend in artificial intelligence-based assistive technology for thoracic imaging. Reviewed International journal

Masahiro Yanagawa, Rintaro Ito, Taiki Nozaki, Tomoyuki Fujioka, Akira Yamada, Shohei Fujita, Koji Kamagata, Yasutaka Fushimi, Takahiro Tsuboyama, Yusuke Matsui, Fuminari Tatsugami, Mariko Kawamura, Daiju Ueda, Noriyuki Fujima, Takeshi Nakaura, Kenji Hirata, Shinji Naganawa

La Radiologia medica Vol. 128 ( 10 ) page： 1236 - 1249 2023.10

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

Although there is no solid agreement for artificial intelligence (AI), it refers to a computer system with intelligence similar to that of humans. Deep learning appeared in 2006, and more than 10 years have passed since the third AI boom was triggered by improvements in computing power, algorithm development, and the use of big data. In recent years, the application and development of AI technology in the medical field have intensified internationally. There is no doubt that AI will be used in clinical practice to assist in diagnostic imaging in the future. In qualitative diagnosis, it is desirable to develop an explainable AI that at least represents the basis of the diagnostic process. However, it must be kept in mind that AI is a physician-assistant system, and the final decision should be made by the physician while understanding the limitations of AI. The aim of this article is to review the application of AI technology in diagnostic imaging from PubMed database while particularly focusing on diagnostic imaging in thorax such as lesion detection and qualitative diagnosis in order to help radiologists and clinicians to become more familiar with AI in thorax.

DOI： 10.1007/s11547-023-01691-w

MOGADのGlymphatic systemのDTI-ALPSを用いた解析 Reviewed

宮地真由, 富沢雄二, 星野泰延, コッス・ダビデ, 萩原彰文, 鎌形康司, 関根永久, 高林海斗, 田岡俊昭, 仲谷元, 横山和正, 長縄慎二, 青木茂樹, 服部信孝

臨床神経学 Vol. 63 ( Suppl. ) page： S275 - S275 2023.9

A Brain Morphometry Study with Across-Site Harmonization Using a ComBat-Generalized Additive Model in Children and Adolescents. Reviewed International journal

Tadashi Shiohama, Norihide Maikusa, Masahiro Kawaguchi, Jun Natsume, Yoshiyuki Hirano, Keito Saito, Jun-Ichi Takanashi, Jacob Levman, Emi Takahashi, Koji Matsumoto, Hajime Yokota, Shinya Hattori, Keita Tsujimura, Daisuke Sawada, Tomoko Uchida, Tomozumi Takatani, Katsunori Fujii, Shinji Naganawa, Noriko Sato, Hiromichi Hamada

Diagnostics (Basel, Switzerland) Vol. 13 ( 17 ) 2023.9

Language：English Publishing type：Research paper (scientific journal)

Regional anatomical structures of the brain are intimately connected to functions corresponding to specific regions and the temporospatial pattern of genetic expression and their functions from the fetal period to old age. Therefore, quantitative brain morphometry has often been employed in neuroscience investigations, while controlling for the scanner effect of the scanner is a critical issue for ensuring accuracy in brain morphometric studies of rare orphan diseases due to the lack of normal reference values available for multicenter studies. This study aimed to provide across-site normal reference values of global and regional brain volumes for each sex and age group in children and adolescents. We collected magnetic resonance imaging (MRI) examinations of 846 neurotypical participants aged 6.0-17.9 years (339 male and 507 female participants) from 5 institutions comprising healthy volunteers or neurotypical patients without neurological disorders, neuropsychological disorders, or epilepsy. Regional-based analysis using the CIVET 2.1.0. pipeline provided regional brain volumes, and the measurements were across-site combined using ComBat-GAM harmonization. The normal reference values of global and regional brain volumes and lateral indices in our study could be helpful for evaluating the characteristics of the brain morphology of each individual in a clinical setting and investigating the brain morphology of ultra-rare diseases.

DOI： 10.3390/diagnostics13172774

Four-dimensional Flow MRI Assessment of Portal Hemodynamics and Hepatic Regeneration after Portal Vein Embolization. Reviewed International journal

Ryota Hyodo, Yasuo Takehara, Takashi Mizuno, Kazushige Ichikawa, Ryota Horiguchi, Shoji Kawakatsu, Takashi Mizuno, Tomoki Ebata, Shinji Naganawa, Ning Jin, Yoshito Ichiba

Radiology Vol. 308 ( 3 ) page： e230709 2023.9

Language：English Publishing type：Research paper (scientific journal)

Background Percutaneous transhepatic portal vein (PV) embolization (PVE) is a standard preoperative procedure for advanced biliary cancer when the future liver remnant (FLR) is insufficient, yet the effect of this procedure on portal hemodynamics is still unclear. Purpose To assess whether four-dimensional (4D) MRI flowmetry can be used to estimate FLR volume and to identify the optimal time for this measurement. Materials and Methods This prospective single-center study enrolled consecutive adult patients with biliary cancer who underwent percutaneous transhepatic PVE for the right liver between June 2020 and November 2022. Portal hemodynamics were assessed using 4D flow MRI before PVE and within 1 day (0-day group) or 3-4 days (3-day group) after PVE. FLR volume was measured using CT before PVE and after PVE but before surgery. Blood flow changes were analyzed with the Wilcoxon signed rank test, and correlations with Spearman rank correlation. Results The 0-day group included 24 participants (median age, 72 years [IQR, 69-77 years]; 17 male participants), and the 3-day group included 13 participants (median age, 71 years [IQR, 68-78 years]; eight male participants). Both groups showed increased left PV (LPV) flow rate after PVE (0-day group: from median 3.72 mL/sec [IQR, 2.83-4.55 mL/sec] to 9.48 mL/sec [IQR, 8.12-10.7 mL/sec], P < .001; 3-day group: from median 3.65 mL/sec [IQR, 2.14-3.79 mL/sec] to 8.16 mL/sec [IQR, 6.82-8.98 mL/sec], P < .001). LPV flow change correlated with FLR volume change relative to the number of days from PVE to presurgery CT only in the 3-day group (ρ = 0.62, P = .02; 0-day group, P = .11). The output of the regression equation for estimating presurgery FLR volume correlated with CT-measured volume (ρ = 0.78; P = .002). Conclusion Four-dimensional flow MRI demonstrated increased blood flow in residual portal branches 3-4 days after PVE, offering insights for estimating presurgery FLR volume. Published under a CC BY 4.0 license. Supplemental material is available for this article. See also the editorial by Roldán-Alzate and Oechtering in this issue.

DOI： 10.1148/radiol.230709

From pituitary adenoma to PitNET: it is time to discuss PitNET/pituitary adenoma. Reviewed

Yasutaka Fushimi, Toshiaki Taoka, Shinji Naganawa

Japanese journal of radiology Vol. 41 ( 8 ) page： 787 - 788 2023.8

Prognostic impact of EGFR/ALK alterations in leptomeningeal metastasis from lung adenocarcinoma treated with whole-brain radiotherapy. Reviewed International journal

Hidekazu Oyoshi, Hidenari Hirata, Yasuhiro Hirano, Sadamoto Zenda, Yuzheng Zhou, Kento Tomizawa, Takeshi Fujisawa, Masaki Nakamura, Hidehiro Hojo, Atsushi Motegi, Shun-Ichiro Kageyama, Yoshitaka Zenke, Koichi Goto, Shunichi Ishihara, Shinji Naganawa, Tetsuo Akimoto

Clinical & experimental metastasis Vol. 40 ( 5 ) page： 407 - 413 2023.7

Language：English Publishing type：Research paper (scientific journal)

The prognosis and prognostic factors of patients receiving whole-brain radiotherapy (WBRT) for leptomeningeal metastasis (LM) from lung adenocarcinoma have not been established. Particularly, the impact of EGFR mutations and ALK rearrangements on survival remains unclear. This retrospective study evaluated the prognosis and prognostic factors of patients receiving WBRT for LM. We evaluated overall survival (OS) from WBRT initiation and clinical variables in 80 consecutive patients receiving WBRT for LM from lung adenocarcinoma at our institution between June 2013 and June 2021. After a median follow-up of 5.2 (range 0.5-56.5) months, the median OS was 6.2 months (95% CI 4.4-12.4). Of the 80 patients, 51 were classified as EGFR/ALK mutant (EGFR: 44; ALK: 6; both: 1) and 29 as wild-type. The median OS was 10.4 (95% CI 5.9-20.9) versus 3.8 (95% CI 2.5-7.7) months in the EGFR/ALK-mutant versus wild-type patients (HR = 0.49, P = 0.0063). Multivariate analysis indicated that EGFR/ALK alterations (HR = 0.54, P = 0.021) and Eastern Cooperative Oncology Group performance status (ECOG PS) of 0-1 (HR = 0.25, P < 0.001) were independent factors associated with favorable OS. Among the patients who underwent brain MRI before and after WBRT, intracranial progression-free survival was longer in the 26 EGFR/ALK-mutant than 13 wild-type patients (HR = 0.31, P = 0.0039). Although the prognosis of patients receiving WBRT for LM remains poor, EGFR/ALK alterations and good ECOG PS may positively impact OS in those eligible for WBRT.

DOI： 10.1007/s10585-023-10225-7

Comparative examination of the pons and corpus callosum as reference regions for quantitative evaluation in positron emission tomography imaging for Alzheimer’s disease using 11C-Pittsburgh Compound-B Invited Reviewed Open Access

Tomohiro Tada, Kazuhiro Hara, Naotoshi Fujita, Yoshinori Ito, Hiroshi Yamaguchi, Reiko Ohdake, Kazuya Kawabata, Aya Ogura, Toshiyasu Kato, Takamasa Yokoi, Michihito Masuda, Shinji Abe, Shinichi Miyao, Shinji Naganawa, Masahisa Katsuno, Hirohisa Watanabe, Gen Sobue, Katsuhiko Kato

Annals of Nuclear Medicine Vol. 37 ( 7 ) page： 410 - 418 2023.7

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

Abstract

Objectives

Standardised uptake value ratio (SUVR) is usually obtained by dividing the SUV of the region of interest (ROI) by that of the cerebellar cortex. Cerebellar cortex is not a valid reference in cases where amyloid β deposition or lesions are present. Only few studies have evaluated the use of other regions as references. We compared the validity of the pons and corpus callosum as reference regions for the quantitative evaluation of brain positron emission tomography (PET) using 11C-PiB compared to the cerebellar cortex.

Methods

We retrospectively evaluated data from 86 subjects with or without Alzheimer’s disease (AD). All subjects underwent magnetic resonance imaging, PET imaging, and cognitive function testing. For the quantitative analysis, three-dimensional ROIs were automatically placed, and SUV and SUVR were obtained. We compared these values between AD and healthy control (HC) groups.

Results

SUVR data obtained using the pons and corpus callosum as reference regions strongly correlated with that using the cerebellar cortex. The sensitivity and specificity were high when either the pons or corpus callosum was used as the reference region. However, the SUV values of the corpus callosum were different between AD and HC (p < 0.01).

Conclusions

Our data suggest that the pons and corpus callosum might be valid reference regions.

DOI： 10.1007/s12149-023-01843-y

Other Link： https://link.springer.com/article/10.1007/s12149-023-01843-y/fulltext.html

田岡俊昭先生の2023 ISMRM Senior Fellow 受章を記念して Reviewed

長縄慎二

日本磁気共鳴医学会雑誌 Vol. 43 ( 3 ) 2023.7

Clinical applications of artificial intelligence in liver imaging Invited

Akira Yamada, Koji Kamagata, Kenji Hirata, Rintaro Ito, Takeshi Nakaura, Daiju Ueda, Shohei Fujita, Yasutaka Fushimi, Noriyuki Fujima, Yusuke Matsui, Fuminari Tatsugami, Taiki Nozaki, Tomoyuki Fujioka, Masahiro Yanagawa, Takahiro Tsuboyama, Mariko Kawamura, Shinji Naganawa

Radiologia Medica Vol. 128 ( 6 ) page： 655 - 667 2023.6

Language：English Publishing type：Research paper (scientific journal)

This review outlines the current status and challenges of the clinical applications of artificial intelligence in liver imaging using computed tomography or magnetic resonance imaging based on a topic analysis of PubMed search results using latent Dirichlet allocation. LDA revealed that “segmentation,” “hepatocellular carcinoma and radiomics,” “metastasis,” "fibrosis," and "reconstruction" were current main topic keywords. Automatic liver segmentation technology using deep learning is beginning to assume new clinical significance as part of whole-body composition analysis. It has also been applied to the screening of large populations and the acquisition of training data for machine learning models and has resulted in the development of imaging biomarkers that have a significant impact on important clinical issues, such as the estimation of liver fibrosis, recurrence, and prognosis of malignant tumors. Deep learning reconstruction is expanding as a new technological clinical application of artificial intelligence and has shown results in reducing contrast and radiation doses. However, there is much missing evidence, such as external validation of machine learning models and the evaluation of the diagnostic performance of specific diseases using deep learning reconstruction, suggesting that the clinical application of these technologies is still in development.

DOI： 10.1007/s11547-023-01638-1

Retrospective non-inferiority study of stereotactic radiosurgery for more than ten brain metastases Reviewed

Naoya Nagai, Yutaro Koide, Yurika Shindo, Shingo Hashimoto, Hiroyuki Tachibana, Takeshi Kodaira, Shunichi Ishihara, Shinji Naganawa

Journal of Neuro-Oncology Vol. 163 ( 2 ) page： 385 - 395 2023.6

もやもや病にGlymphatic system機能不全は存在するか? DTI-ALPS indexによる評価 Reviewed

原祥子, 菊田潤子, 高林海斗, 鎌形康司, 林志保里, 稲次基希, 田中洋次, 堀正明, 石井賢二, 成相直, 田岡俊昭, 長縄慎二, 青木茂樹, 前原健寿

日本磁気共鳴医学会雑誌 Vol. 43 ( 2 ) page： 56 - 59 2023.5

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：(一社)日本磁気共鳴医学会

もやもや病のGlymphatic system(GS)について、DTI analysis along the perivascular space(DTI-ALPS index)を用いて検討した。成人もやもや病患者46名(男性13名、女性33名、平均38.4歳)と年齢、性別の合致した健常人34名(男性7名、女性27名、平均40.1歳)を対象とし、3T機でEPIシーケンスによる拡散MRIとMPRAGE法による3DT1強調像を撮影した。患者全例で認知機能検査としてTrail Making Test(TMT)を行った。もやもや病のDTI-ALPS indexは健常人より有意に低く、脳実質水成分と負の相関を示した。DTI-ALPS indexはPETのパラメータのうち、脳灌流圧の逆波である平均通過時間(MTT)と有意な負の相関を示した。遂行機能障害が強いほど点数が高くなるTMT-Bは左半球のDTI-ALPS indexと有意な負の相関を示した。もやもや病では脳循環不全の程度に応じてGS機能不全が存在し、脳実質の水成分増加を生じ、認知機能障害と関連する可能性があると考えられた。

もやもや病にGlymphatic system機能不全は存在するか？―DTI-ALPS indexによる評価― Reviewed

原祥子、菊田潤子、高林海斗、鎌形康司、林志保里、稲次基希、田中洋次、堀正明、石井賢二、成相直、田岡俊昭、長縄慎二、青木茂樹、前原健寿

日本磁気共鳴医学会雑誌 Vol. 43 ( 2 ) page： 56 - 59 2023.5

ALPS-indexを用いた糖尿病と糖尿病前期の病態におけるGlymphatic systemの評価 Reviewed International coauthorship

Rukeye Tuerxun、鎌形康司、Christina Andica、内田　航、斎藤勇哉、高林海斗、加賀英義、染谷由希、明石敏昭、和田昭彦、田端宏樹、内藤仁嗣、田村好史、田岡俊昭、長縄慎二、河盛隆造、綿田裕孝、青木茂樹

日本磁気共鳴医学会雑誌 Vol. 43 ( 2 ) page： 60 - 62 2023.5

Labyrinthine calcification in ears with otitis media and antineutrophil cytoplasmic antibody-associated vasculitis (OMAAV): A report of two cases. Reviewed International journal

Tadao Yoshida, Masumi Kobayashi, Satofumi Sugimoto, Shinji Naganawa, Michihiko Sone

Auris, nasus, larynx Vol. 50 ( 2 ) page： 299 - 304 2023.4

Language：English Publishing type：Research paper (scientific journal)

Otitis media with antineutrophil cytoplasmic antibody-associated vasculitis (OMAAV) has been proposed as a new type of otitis media. The hearing loss caused by OMAAV can be expected to improve with early detection and intervention, but if it continues to worsen and leads to deafness, it is challenging to recover the patient's hearing. When bilateral deafness occurs, cochlear implant (CI) surgery is the only way to improve hearing. Here, Case 1 showed unilateral cochlear calcification, and Case 2 showed bilateral cochlear calcification. In Case 1, CI surgery was performed on the ear lacking calcification, and in Case 2 it was performed on the ear with milder calcification. In Case 2, granulation was present from the tympanic space to the mastoid, the round window was closed, and the basal turn of the cochlea was narrowed. Such calcification of the cochlea caused by OMAAV has not been reported so far. It is essential to detect these changes by computed tomography scans at an early stage and to perform CI surgery at an appropriate time, because hearing improvements are not expected in patients who become deaf because of OMAAV.

DOI： 10.1016/j.anl.2022.01.004

Postendovascular Aneurysmal Repair Increase in Local Energy Loss for Fusiform Abdominal Aortic Aneurysm: Assessments With 4D flow MRI. Reviewed International journal

Ryota Horiguchi, Yasuo Takehara, Masataka Sugiyama, Ryota Hyodo, Tomohiro Komada, Masaya Matsushima, Shinji Naganawa, Takashi Mizuno, Yasuo Sakurai, Masayuki Sugimoto, Hiroshi Banno, Kimihiro Komori, Keiichi Itatani

Journal of magnetic resonance imaging : JMRI Vol. 57 ( 4 ) page： 1199 - 1211 2023.4

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Although endovascular aneurysmal repair (EVAR) is a preferred treatment for abdominal aortic aneurysm (AAA) owing to its low invasiveness, its impact on the local hemodynamics has not been fully assessed. PURPOSE: To elucidate how EVAR affects the local hemodynamics in terms of energy loss (EL). STUDY TYPE: Prospective single-arm study. FIELD STRENGTH/SEQUENCE: A 3.0 T/4D flow MRI using a phase-contrast three-dimensional cine-gradient-echo sequence. POPULATION: A total of 13 consecutive patients (median [interquartile range] age: 77.0 [73.0, 78.8] years, 11 male) scheduled for EVAR as an initial treatment for fusiform AAA. ASSESSMENT: 4D flow MRI covering the abdominal aorta and bilateral common iliac arteries and the corresponding stent-graft (SG) lumen was performed before and after EVAR. Plasma brain natriuretic peptide (BNP) was measured within 1 week before and 1 month after EVAR. The hemodynamic data, including mean velocity and the local EL, were compared pre-/post-EVAR. EL was correlated with AAA neck angle and with BNP. Patients were subdivided into deformed (N = 5) and undeformed SG subgroups (N = 8) and pre-/post-EVAR BNP compared in each. STATISTICS: Parametric or nonparametric methods. Spearman's rank correlation coefficients (r). The interobserver/intraobserver variabilities with Bland-Altman plots. A P value < 0.05 is considered significant. RESULTS: The mean velocity (cm/sec) at the AAA was five times greater after EVAR: 4.79 ± 0.32 vs. 0.91 ± 0.02. The total EL (mW) increased by 1.7 times after EVAR: 0.487 (0.420, 0.706) vs. 0.292 (0.192, 0.420). The total EL was proportional to the AAA neck angle pre-EVAR (r = 0.691) and post-EVAR (r = 0.718). BNP (pg/mL) was proportional to the total EL post-EVAR (r = 0.773). In the deformed SG group, EL (0.349 [0.261, 0.416]) increased 2.4-fold to 0.848 (0.597, 1.13), and the BNP 90.3 (53.6, 105) to 100 (67.2, 123) post-EVAR. CONCLUSION: The local EL showed a 1.7-fold increase after EVAR. The larger increase in the EL in the deformed SG group might be a potential concern for frail patients. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

DOI： 10.1002/jmri.28359

門松健治先生のすごさ；高いVision、現実解実現のための行動力 Invited Reviewed

長縄慎二

門松健治教授退任記念誌 page： 75 - 76 2023.4

門松健治先生のすごさ；高いVision、現実解実現のための行動力 Invited Reviewed

長縄慎二

門松健治教授退任記念誌 page： 75 - 76 2023.4

Glymphatic system impairment in nonathlete older male adults who played contact sports in their youth associated with cognitive decline: A diffusion tensor image analysis along the perivascular space study Reviewed International journal

Yuichi Morita, Koji Kamagata, Christina Andica, Kaito Takabayashi, Junko Kikuta, Shohei Fujita, Thomas Samoyeau, Wataru Uchida, Yuya Saito, Hiroki Tabata, Hitoshi Naito, Yuki Someya, Hideyoshi Kaga, Yoshifumi Tamura, Mari Miyata, Toshiaki Akashi, Akihiko Wada, Toshiaki Taoka, Shinji Naganawa, Hirotaka Watada, Ryuzo Kawamori, Osamu Abe, Shigeki Aoki

Frontiers in Neurology Vol. 14 page： 1100736 - 1100736 2023.2

Language：English Publishing type：Research paper (scientific journal) Publisher：Frontiers Media SA

Background and purpose

Exposure to contact sports in youth causes brain health problems later in life. For instance, the repetitive head impacts in contact sports might contribute to glymphatic clearance impairment and cognitive decline. This study aimed to assess the effect of contact sports participation in youth on glymphatic function in old age and the relationship between glymphatic function and cognitive status using the analysis along the perivascular space (ALPS) index.

Materials and methods

A total of 52 Japanese older male subjects were included in the study, including 12 who played heavy-contact sports (mean age, 71.2 years), 15 who played semicontact sports (mean age, 73.1 years), and 25 who played noncontact sports (mean age, 71.3 years) in their youth. All brain diffusion-weighted images (DWIs) of the subjects were acquired using a 3T MRI scanner. The ALPS indices were calculated using a validated semiautomated pipeline. The ALPS indices from the left and right hemispheres were compared between groups using a general linear model, including age and years of education. Furthermore, partial Spearman's rank correlation tests were performed to assess the correlation between the ALPS indices and cognitive scores (Mini-Mental State Examination and the Japanese version of the Montreal Cognitive Assessment [MoCA-J]) after adjusting for age years of education and HbA1c.

Results

The left ALPS index was significantly lower in the heavy-contact and semicontact groups than that in the noncontact group. Although no significant differences were observed in the left ALPS index between the heavy-contact and semicontact groups and in the right ALPS index among groups, a trend toward lower was found in the right ALPS index in individuals with semicontact and heavy-contact compared to the noncontact group. Both sides' ALPS indices were significantly positively correlated with the MoCA-J scores.

Conclusion

The findings indicated the potential adverse effect of contact sports experience in youth on the glymphatic system function in old age associated with cognitive decline.

DOI： 10.3389/fneur.2023.1100736

Neuroimaging findings related to glymphatic system alterations in older adults with metabolic syndrome. Reviewed International journal

Christina Andica, Koji Kamagata, Kaito Takabayashi, Junko Kikuta, Hideyoshi Kaga, Yuki Someya, Yoshifumi Tamura, Ryuzo Kawamori, Hirotaka Watada, Toshiaki Taoka, Shinji Naganawa, Shigeki Aoki

Neurobiology of disease Vol. 177 page： 105990 - 105990 2023.2

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: The glymphatic system is a glial-based perivascular network that promotes brain metabolic waste clearance. Reduced glymphatic flow has been observed in rat models of type 2 diabetes and hypertension, indicating the role of vascular risk factors in the glymphatic system. However, little is known about how vascular risk factors affect the human glymphatic system. The present study aims to assess the relationships between metabolic syndrome (MetS), a cluster of vascular risk factors, and the glymphatic system function using diffusion magnetic resonance imaging (MRI)-based measures of water diffusivity in the glymphatic compartments, including the brain interstitial space and perivascular spaces around the deep medullary vein. We hypothesized that vascular risk factors are associated with glymphatic dysfunction, leading to cognitive impairment in older adults. METHODS: This cross-sectional study assessed 61 older adults (age range, 65-82 years) who had participated in the Bunkyo Health Study, including 15 healthy controls (mean age, 70.87 ± 4.90 years) and 46 individuals with MetS (mean age, 71.76 ± 4.61 years). Fractional volume of extracellular-free water (FW) and an index of diffusion tensor imaging along the perivascular space (DTI-ALPS) were used as indirect indicators of water diffusivity in the interstitial extracellular and perivenous spaces of white matter, respectively. RESULTS: After adjusting for age, sex, years of education, total Fazekas scale, Pittsburgh sleep quality index (PSQI) score, and intracranial volume (ICV), a significantly (P = 0.030; Cohen's d = 1.01) higher FW was observed in individuals with MetS than in the healthy controls. Furthermore, individuals with MetS had a significantly (P = 0.031; Cohen's d = 0.86) lower ALPS index than the healthy controls, with age, sex, years of education, total Fazekas scale, PSQI score, ICV, fractional anisotropy, and mean diffusivity included as confounding factors. Higher FW was significantly associated with lower ALPS index (r = -0.37; P = 0.004). Multiple linear regression (MLR) with backward elimination analyses showed that higher diastolic blood pressure (BP; standardized β = 0.33, P = 0.005) was independently associated with higher FW, whereas higher fasting plasma glucose levels (standardized β = -0.63, P = 0.002) or higher Brinkman index of cigarette consumption cumulative amount (standardized β = -0.27, P = 0.022) were associated with lower ALPS index. The lower ALPS index (standardized β, 0.28; P = 0.040) was associated with poorer global cognitive performance, which was determined using the Japanese version of the Montreal Cognitive Assessment (MOCA-J) scores. Finally, partial correlation analyses showed a significant correlation between higher FW and lower MOCA-J scores (r = -0.35; P = 0.025) and between higher FW and higher diastolic BP (r = 0.32, P = 0.044). CONCLUSION: The present study shows the changes in diffusion MRI-based measures reflected by the higher FW and lower ALPS index in older adults with MetS, possibly due to the adverse effect of vascular risk factors on the glymphatic system. Our findings also indicate the associations between the diffusion MRI-based measures and elevated diastolic BP, hyperglycemia, smoking habit, and poorer cognitive performance. However, owing to the limitations of this study, the results should be cautiously interpreted.

DOI： 10.1016/j.nbd.2023.105990

"Speckled Enhancement" on Gd-EOB-DTPA Enhanced MR Imaging of Primary Hepatic Mucosa-associated Lymphoid Tissue Lymphoma. Reviewed

自己免疫性膵炎の画像診断：コンピュータ断層撮影と磁気共鳴画像法 Reviewed

小川　浩、竹原康雄、長縄慎二

Jpn. J Med Ultrasonics. Vol. 50 ( 1 ) page： 39 - 45 2023.1

A plea for systematic literature analysis and conclusive study design, comment on: "Systematic review of magnetic resonance imaging for diagnosis of Meniere disease". Reviewed International journal

Robert Gürkov, Krisztina Barath, Bert de Foer, Munehisa Fukushima, Michael Gluth, Jermy Hornibrook, Nicolas Perez-Fernandez, Ilmari Pyykkö, Michihiko Sone, Shin-Ichi Usami, Wuqing Wang, Jing Zou, Shinji Naganawa

Journal of vestibular research : equilibrium & orientation Vol. 33 ( 2 ) page： 151 - 157 2023

Ryota Hyodo, Yasuo Takehara, Ayumi Nishida, Masaya Matsushima, Shinji Naganawa

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 22 ( 3 ) page： 273 - 281 2023

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: To elucidate MRI features of primary hepatic mucosa-associated lymphoid tissue (MALT) lymphoma, particularly, the "speckled enhancement" on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI. METHODS: The institutional review board approved this retrospective observational study and waived informed consent. Using our picture archiving and communication systems and electronic medical records, five patients histopathologically diagnosed as hepatic MALT lymphoma and clinically confirmed as primary lesions who had undergone dynamic contrast-enhanced (DCE)-CT and DCE-MRI with Gd-EOB-DTPA were identified from September 2009 to December 2020. Two radiologists assessed their CT and MRI data in consensus with a pathologist's advice. RESULTS: Overall, five lesions in five patients were included in this study. Precontrast CT showed hypoattenuation in all lesions. In the arterial phase of DCE-CT, four lesions (80%) showed hyperattenuation, whereas all lesions showed iso- to hypoattenuation in the delayed phase. A vessel penetration sign was also observed in all lesions. On MRI, all lesions showed hypointensity on T1-weighted images, hyperintensity on T2-weighted images, and restricted diffusion on diffusion-weighted images. Both DCE-CT and DCE-MRI with Gd-EOB-DTPA showed similar enhancement patterns, except for the hepatocyte phase. Notably, however, four out of five lesions showed characteristic "speckled enhancement" that refers to punctate positive enhancements within the low signal lesions on the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI pathologically confirmed to be hepatocyte clusters that remained in the tumor. CONCLUSION: Primary hepatic MALT lymphomas were characterized by arterial phase enhancement, restricted diffusion, vessel penetration sign, and more specifically "speckled enhancement" in the hepatobiliary phase of DCE-MRI with Gd-EOB-DTPA.

DOI： 10.2463/mrms.mp.2021-0069

Peripheral Retinal Leakage after Intravenous Administration of a Gadolinium-based Contrast Agent: Age Dependence, Temporal and Inferior Predominance and Potential Implications for Eye Homeostasis. Reviewed

Shinji Naganawa, Rintaro Ito, Mariko Kawamura, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 22 ( 1 ) page： 45 - 55 2023

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Peripheral retinal leakage (PRL) of contrast medium from the ora serrata (i.e., the peripheral part of the retina) was recently reported in normal eyes using ultra-widefield fluorescein angiography. We occasionally see PRL of gadolinium-based contrast agents (GBCAs) in the vitreous from the temporal and inferior sides of the ora serrata on MR images of subjects without ophthalmic disease. In this study, we retrospectively evaluated these MR images to determine if PRL was associated with aging. We also evaluated whether the initial leakage appeared in the temporal and inferior sides, and whether there was uniform distribution within the vitreous after 24 hours. METHODS: In 127 subjects (9 volunteers, 85 patients with sudden deafness, and 33 patients with a suspicion of endolymphatic hydrops), pre- and post-contrast-enhanced heavily T2-weighted 3D-fluid attenuated inversion recovery (FLAIR) images were obtained. The presence or absence of PRL was subjectively evaluated. For patients with a suspicion of endolymphatic hydrops, 3D-real inversion recovery (IR) images were also obtained at pre-, 10 mins, 4 hours, and 24 hours after intravenous administration (IV) of GBCA. Four circular ROIs were placed in the vitreous humor and the signal intensity was measured. RESULTS: In the cases with PRL (n = 88) and without PRL (n = 47), the median age was 59 and 47 years, respectively (P = 0.001). At 4 hours after IV-GBCA, the mean signal increase in the inferior temporal ROI was greater than all the other ROIs. At 24 hours after IV-GBCA, no significant difference in signal intensity was observed for the four ROIs. CONCLUSION: PRL of GBCA is age-dependent and occurs mainly from the inferior temporal side of the ora serrata. The contrast effect was uniformly distributed at 24 hours after IV-GBCA. Future observations in a variety of diseases will determine the clinical significance of these findings.

DOI： 10.2463/mrms.mp.2021-0100

Pitfalls of Using T2-contrast Enhancement Techniques in 3D-FLAIR to Detect Endolymphatic Hydrops. Reviewed

Yutaka Kato, Shinji Naganawa, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 22 ( 3 ) page： 335 - 344 2023

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: To determine whether T2-contrast enhancement techniques can be used to diagnose endolymphatic hydrops, we compared fluid signal artifacts with and without T2-contrast enhancement techniques in 3D fluid-attenuated inversion recovery (3D-FLAIR). METHODS: We prepared a custom-made phantom consisting of eight tubes half-filled with saline. Images were obtained using four 3D-FLAIR: without T2-contrast enhancement (Normal), with non-selective T2-inversion recovery (T2-IR), and two with non-selective T2 preparation IR (T2-prep). Scans were performed with and without rice covering the phantom to simulate minimal and severe B0-inhomogeneity conditions. The average signal intensity (SI) values of eight saline tubes were compared between the four sequences and between each other. Comparisons were performed for all measurement slices and the central 10 slices. The images using T2-contrast enhancement technique were obtained from a volunteer and a patient suspected of Meniere's disease. RESULTS: The Normal sequence SI for all slices was significantly lower than that for the other sequences, with smaller standard deviation (SD) and no outliers. Several outliers were detected in the other sequences. The SDs and outliers were larger without rice than with rice. When the central 10 slices with rice, the T2-IR had a significantly higher SI with more outliers compared with the Normal sequence. The T2-prep had no outliers and SIs that were comparable to those of the Normal sequence. However, without rice, the T2-IR and T2-prep sequences had significantly higher SIs with outliers and larger SDs compared to the Normal sequence. In the corresponding images, the Normal sequence achieved excellent fluid suppression, whereas the T2-IR and T2-prep sequences showed high-signal artifacts. Imperfect fluid suppressions were observed in the volunteer image and the endolymphatic hydrops on the post-gadolinium image differed in size and shape in the non-injected T2-IR in the patient image. CONCLUSION: T2-contrast enhancement techniques should be used with caution in 3D-FLAIR for diagnosing endolymphatic hydrops.

DOI： 10.2463/mrms.mp.2022-0017

Assessing the Complicated Venous Hemodynamics and Therapeutic Outcomes of Budd-Chiari Syndrome with Respiratory-gated 4D Flow MR Imaging During the Expiratory and Inspiratory Phases. Reviewed

Ryota Hyodo, Yasuo Takehara, Takashi Mizuno, Kazushige Ichikawa, Shinya Yokoyama, Yoji Ishizu, Shinji Naganawa

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 22 ( 1 ) page： 1 - 6 2023

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

A man in his 50s with Budd-Chiari syndrome diagnosed with the suprahepatic inferior vena cava (IVC) obstruction on CT was assessed using 4D Flow MRI before and after balloon angioplasty. 4D Flow MRI acquired in two respiratory phases, depicted complex hemodynamic and respiratory variability, and a jet stream at the narrowed channel of the membranous IVC. Post-interventional 4D Flow MRI showed that the IVC blood flow increased with corrected flow directions in the infrarenal IVC.

DOI： 10.2463/mrms.ici.2021-0110

Parasagittal Cystic Lesions May Arise from the Pial Sheath around the Cortical Venous Wall. Reviewed

Shinji Naganawa, Rintaro Ito, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 22 ( 1 ) page： 143 - 146 2023

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)

It has been reported that perivenous cystic structures near the parasagittal dura are associated with the leakage of gadolinium-based contrast agents at 4 hours after intravenous administration. The origin of such cystic structures remains unknown. While reading many cases of MR cisternography, we noticed that some of the cystic structures appeared to connect to the perivenous subpial space. This new imaging finding might facilitate future research of the waste clearance system for the central nervous system.

DOI： 10.2463/mrms.bc.2021-0141

Current State of Artificial Intelligence in Clinical Applications for Head and Neck MR Imaging Reviewed

Noriyuki Fujima, Koji Kamagata, Daiju Ueda, Shohei Fujita, Yasutaka Fushimi, Masahiro Yanagawa, Rintaro Ito, Takahiro Tsuboyama, Mariko Kawamura, Takeshi Nakaura, Akira Yamada, Taiki Nozaki, Tomoyuki Fujioka, Yusuke Matsui, Kenji Hirata, Fuminari Tatsugami, Shinji Naganawa

Magnetic Resonance in Medical Sciences Vol. 22 ( 4 ) page： 401 - 414 2023

Stereotactic radiotherapy for ventricular tachycardia: A study protocol. Reviewed International journal

Mariko Kawamura, Masafumi Shimojo, Yasuya Inden, Takeshi Kamomae, Kuniyasu Okudaira, Tomohiro Komada, Sumire Aoki, Yurika Shindo, Ryotaro Yasui, Yusuke Yanagi, Masayuki Okumura, Takehiro Yamada, Yuka Kozai, Yumi Oie, Yutaka Kato, Shunichi Ishihara, Toyoaki Murohara, Shinji Naganawa

F1000Research Vol. 12 page： 798 - 798 2023

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Currently, the standard curative treatment for ventricular tachycardia (VT) and ventricular fibrillation (VF) is radiofrequency catheter ablation. However, when the VT circuit is deep in the myocardium, the catheter may not be delivered, and a new, minimally invasive treatment using different energies is desired. METHODS: This is a protocol paper for a feasibility study designed to provide stereotactic radiotherapy for refractory VT not cured by catheter ablation after at least one catheter ablation. The primary end point is to evaluate the short-term safety of this treatment and the secondary endpoint is to evaluate its efficacy as assessed by the reduction in VT episode. Cyberknife M6 radiosurgery system will be used for treatment, and the prescribed dose to the target will be 25Gy in one fraction. The study will be conducted on three patients. CONCLUSION: Since catheter ablation is the only treatment option for VT that is covered by insurance in Japan, there is currently no other treatment for VT/VF that cannot be cured by catheter ablation. We hope that this feasibility study will provide hope for patients who are currently under the stress of ICD activation. TRIAL REGISTRATION: The study has been registered in the Japan Registry of Clinical Trials (jRCTs042230030).

DOI： 10.12688/f1000research.138758.2

Association of MRI Indices of Glymphatic System With Amyloid Deposition and Cognition in Mild Cognitive Impairment and Alzheimer Disease. Reviewed International journal

Koji Kamagata, Christina Andica, Kaito Takabayashi, Yuya Saito, Toshiaki Taoka, Hayato Nozaki, Junko Kikuta, Shohei Fujita, Akifumi Hagiwara, Kouhei Kamiya, Akihiko Wada, Toshiaki Akashi, Katsuhiro Sano, Mitsuo Nishizawa, Masaaki Hori, Shinji Naganawa, Shigeki Aoki

Neurology Vol. 99 ( 24 ) page： E2648 - E2660 2022.12

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND AND OBJECTIVES: The glymphatic system is a whole-brain perivascular network, which promotes CSF/interstitial fluid exchange. Alterations to this system may play a pivotal role in amyloid β (Aβ) accumulation. However, its involvement in Alzheimer's disease (AD) pathogenesis is not fully understood. Here, we investigated the changes in noninvasive MRI measurements related to the perivascular network in patients with mild cognitive impairment (MCI) and AD. Additionally, we explored the associations of MRI measures with neuropsychological score, PET standardized uptake value ratio (SUVR), and Aβ deposition. METHODS: MRI measures, including perivascular space (PVS) volume fraction (PVSVF), fractional volume of free water in white matter (FW-WM), and index of diffusivity along the perivascular space (ALPS index) of patients with MCI, those with AD, and healthy controls from the Alzheimer's Disease Neuroimaging Initiative database were compared. MRI measures were also correlated with the levels of CSF biomarkers, PET SUVR, and cognitive score in the combined subcohort of patients with MCI and AD. Statistical analyses were performed with age, sex, years of education, and APOE status as confounding factors. RESULTS: In total, 36 patients with AD, 44 patients with MCI, and 31 healthy controls were analyzed. Patients with AD had significantly higher total, WM, and basal ganglia PVSVF (Cohen's d = 1.15-1.48; p < 0.001), and FW-WM (Cohen's d = 0.73; p < 0.05) and a lower ALPS index (Cohen's d = 0.63; p < 0.05) than healthy controls. Meanwhile, the MCI group only showed significantly higher total (Cohen's d = 0.99; p < 0.05) and WM (Cohen's d = 0.91; p < 0.05) PVSVF. Low ALPS index was associated with lower CSF Aβ42 (r s = 0.41, p fdr = 0.026), FDG-PET uptake (r s = 0.54, p fdr < 0.001), and worse multiple cognitive domain deficits. High FW-WM was also associated with lower CSF Aβ42 (r s = -0.47, p fdr = 0.021) and worse cognitive performances. CONCLUSION: Our study indicates that changes in PVS-related MRI parameters occur in MCI and AD, possibly due to impairment of the glymphatic system. We also report the associations between MRI parameters and Aβ deposition, neuronal change, and cognitive impairment in AD.

DOI： 10.1212/WNL.0000000000201300

Reproducibility of functional connectivity metrics estimated from resting-state functional MRI with differences in days, coils, and global signal regression Reviewed

Sanae Kato, Epifanio Bagarinao, Haruo Isoda, Shuji Koyama, Hirohisa Watanabe, Satoshi Maesawa, Kazuhiro Hara, Masahisa Katsuno, Shinji Naganawa, Norio Ozaki, Gen Sobue

Radiological Physics and Technology Vol. 15 ( 4 ) page： 298 - 310 2022.12

Interstitial Fluidopathy of the Central Nervous System: An Umbrella Term for Disorders with Impaired Neurofluid Dynamics.

Toshiaki Taoka, Rintaro Ito, Rei Nakamichi, Toshiki Nakane, Hisashi Kawai, Shinji Naganawa

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 23 ( 1 ) page： 1 - 13 2022.11

Language：English Publishing type：Research paper (scientific journal)

Interest in interstitial fluid dynamics has increased since the proposal of the glymphatic system hypothesis. Abnormal dynamics of the interstitial fluid have been pointed out to be an important factor in various pathological statuses. In this article, we propose the concept of central nervous system interstitial fluidopathy as a disease or condition in which abnormal interstitial fluid dynamics is one of the important factors for the development of a pathological condition. We discuss the aspects of interstitial fluidopathy in various diseases, including Alzheimer's disease, Parkinson's disease, normal pressure hydrocephalus, and cerebral small vessel disease. We also discuss a method called "diffusion tensor image analysis along the perivascular space" using MR diffusion images, which is used to evaluate the degree of interstitial fluidopathy or the activity of the glymphatic system.

DOI： 10.2463/mrms.rev.2022-0012

17O-labeled water distribution in the human inner ear: Insights into lymphatic dynamics and vestibular function. Reviewed International journal

Tadao Yoshida, Shinji Naganawa, Masumi Kobayashi, Satofumi Sugimoto, Naomi Katayama, Tsutomu Nakashima, Yutaka Kato, Kazushige Ichikawa, Hiroshi Yamaguchi, Kazuki Nishida, Michihiko Sone

Frontiers in neurology Vol. 13 page： 1016577 - 1016577 2022.11

Language：English Publishing type：Research paper (scientific journal)

We evaluated the inner ear distribution of 17O-labeled saline administered to the human tympanic cavity. Magnetic resonance imaging was performed after intratympanic administration in five healthy volunteers and one patient with cochlear endolymphatic hydrops. In all volunteers, 17O-labeled water permeated the cochlear basal turn and vestibule at 30 min and disappeared gradually within 2-4 h. All participants experienced positional vertigo lasting a few hours to a few days. Visualization of 17O-labeled water distribution in the endolymphatic space of the posterior ampulla showed indistinct separation of endolymph and perilymph in the cochlea and most of the vestibule in all participants. Intralabyrinthine distribution of 17O-labeled water differed from that in previous reports of intratympanically administered gadolinium-based contrast agent. 17O-labeled water in the endolymphatic space may cause heavier endolymph and positional vertigo. These results of this study may add new insights for investigating the distribution and the effects of molecules in the inner ear after the intratympanic administration in living humans.

DOI： 10.3389/fneur.2022.1016577

4D Flow MRI in the portal venous system: imaging and analysis methods, and clinical applications. Reviewed International journal

Ryota Hyodo, Yasuo Takehara, Shinji Naganawa

La Radiologia medica Vol. 127 ( 11 ) page： 1181 - 1198 2022.11

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

Thus far, ultrasound, CT, and 2D cine phase-contrast MRI has been adopted to evaluate blood flow and vascular morphology in the portal venous system; however, all these techniques have some shortcomings, such as limited field of view and difficulty in accurately evaluating blood flow. A new imaging technique, namely 3D cine phase-contrast (4D Flow) MRI, can acquire blood flow data of the entire abdomen at once and in a time-resolved manner, allowing visual, quantitative, and comprehensive assessment of blood flow in the portal venous system. In addition, a retrospective blood flow analysis, i.e., "retrospective flowmetry," is possible. Although the development of 4D Flow MRI for the portal system has been delayed compared to that for the arterial system owing to the lower flow velocity of the portal venous system and the presence of respiratory artifacts, several useful reports have recently been published as the technology has advanced. In the first part of this narrative review article, technical considerations of image acquisition and analysis methods of 4D Flow MRI for the portal venous system and the validations of their results are described. In the second part, the current clinical application of 4D Flow MRI for the portal venous system is reviewed.

DOI： 10.1007/s11547-022-01553-x

Iodinated Contrast Media Substitution to Prevent Recurrent Hypersensitivity Reactions: A Systematic Review and Meta-Analysis. Reviewed International journal

Hiroyasu Umakoshi, Takashi Nihashi, Akira Takada, Naoki Hirasawa, Shunichi Ishihara, Yasuo Takehara, Shinji Naganawa, Matthew S Davenport, Teruhiko Terasawa

Radiology Vol. 305 ( 2 ) page： 341 - 349 2022.11

Language：English Publishing type：Research paper (scientific journal)

Background Changing iodinated contrast media (ICM) may reduce the risk of recurrent ICM-induced hypersensitivity reactions in patients with a prior reaction. Purpose To perform a systematic review on the effectiveness of ICM change in comparison with no change to prevent recurrent ICM immediate hypersensitivity reactions. Materials and methods Multiple data bases were searched without language restriction between January 1990 and August 2021 to identify comparative studies of any design that included patients with a prior ICM hypersensitivity reaction to low-osmolality ICM and re-exposure to intravascular ICM. The methods used included a duplicate assessment of eligibility, double extraction of quantitative data, validity assessment, and random-effects meta-analysis. The primary outcome was the incidence of all-grade immediate recurrent hypersensitivity reactions. Secondary outcomes were the incidence of severe immediate recurrent hypersensitivity reactions and other adverse events associated with ICM change. Results Six retrospective observational studies at moderate to severe risk of bias assessed 7155 adult patients (4329 in the ICM change group and 2826 in the no-change group). Studies adopted nonstandardized switching methods, and the proportions of the ICM change group ranged between 19% (five of 27 examinations) and 80% (3104 of 3880 examinations). A Bayesian meta-analysis revealed that changing ICM was associated with a reduced risk of recurrent hypersensitivity reaction by 61% (risk ratio = 0.39; 95% credible interval [CrI]: 0.24, 0.58). The wide-ranging estimates of risk reduction were not explained by the risk of bias ratings, the event rates in the no-change group, the index-reaction severity, or the co-administered nonstandard premedication. Rare severe recurrent reactions (five studies with five events) precluded a conclusion (risk ratio = 0.34, favoring ICM change; CrI: 0.01, 3.74). Adverse events associated with ICM change were not reported. Conclusion In observational evidence of limited quality, iodinated contrast media (ICM)-change was associated with a reduced risk of recurrent immediate hypersensitivity reaction in patients with a prior ICM-induced hypersensitivity reaction. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by McDonald in this issue.

DOI： 10.1148/radiol.220370

Impact of tissue properties on time-dependent alterations in apparent diffusion coefficient: A phantom study using oscillating gradient spin-echo and pulsed gradient spin-echo sequences Reviewed

Kazushige Ichikawa, Toshiaki Taoka, Masanori Ozaki, Mayuko Sakai, Hiroshi Yamaguchi, Shinji Naganawa

Japanese Journal of Radiology Vol. 40 ( 9 ) page： 970 - 978 2022.9

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The purpose of this study was to investigate whether the changes in apparent diffusion coefficients (ADCs) due to differences in diffusion time reflect tissue properties in actual measurements of phantoms. MATERIALS AND METHODS: Various n-alkane phantoms and sucrose/collagen phantoms with various collagen densities were set up with and without polyvinyl alcohol (PVA) foam with an average pore diameter of 300 μm. Thus, n-alkanes or sucrose/collagen represented substrate viscosity and the presence of PVA foam represented tissue structure with septum. Diffusion-weighted images with various diffusion times (7.71-60 ms) were acquired using pulsed-gradient spin-echo (PGSE) and oscillating-gradient spin-echo (OGSE) sequences. The ADCs of the phantoms with and without PVA foam were calculated. RESULTS: The ADCs of some of the phantoms without PVA decreased with diffusion times decreased. In the n-alkane phantoms, only C8H18 showed significantly different ADCs depending on the use of PVA foam in the OGSE sequence. On the other hand, sucrose/collagen phantoms showed significant differences according to diffusion time. The ADCs of the phantoms decreased as the molecular size of the n-alkanes or collagen density of the sucrose/collagen phantom increased. Compared to phantoms without PVA foam, the ADC of the phantoms with PVA foam decreased as the diffusion time increased. CONCLUSION: Changes in ADCs due to differences in diffusion time reflect tissue properties in actual measurements of phantoms. These changes in ADCs can be used for tissue characterization in vivo.

DOI： 10.1007/s11604-022-01281-2

Diffusion-weighted image analysis along the perivascular space (DWI-ALPS) for evaluating interstitial fluid status: age dependence in normal subjects. Reviewed

Toshiaki Taoka, Rintaro Ito, Rei Nakamichi, Toshiki Nakane, Mayuko Sakai, Kazushige Ichikawa, Hisashi Kawai, Shinji Naganawa

Japanese journal of radiology Vol. 40 ( 9 ) page： 894 - 902 2022.9

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The purpose of this study was to evaluate the interstitial fluid status in a wide range of age groups using diffusion-weighted image analysis along the perivascular space (DWI-ALPS) method, which is a simplified variation of diffusion tensor image analysis along the perivascular space (DTI-ALPS). MATERIALS AND METHODS: This retrospective study included data from 128 patients who underwent clinical magnetic resonance imaging (MRI) studies, including DWI, and were found to have no abnormal findings in the brain on MRI. Three motion-probing gradients of the DWI were applied in an orthogonal direction to the imaging plane. Apparent diffusion coefficient images in the x-, y-, and z-axes were retrospectively generated, and composite color images were created to locate the projection and association fiber area on the slice including the body of the lateral ventricle. ALPS indices were calculated, and correlations with age were evaluated using linear and second-degree regression analysis. Linear regression analysis was also performed for a subgroup of patients older than 40 years. In addition, an analysis of variance (ANOVA) test among the generations was performed. RESULTS: The linear regression analysis between age and the ALPS index showed a correlation coefficient of -0.20 for all age group and -0.51 for the subgroup older than 40 years. The second-degree regression analysis showed a correlation coefficient of 0.39. ANOVA showed that the 40's generation showed a statistically significant higher value of ALPS index compared to all other generations except for the 30's generation. While, the 70's generation showed a statistically significant lower value of the ALPS index compared to all other generations. CONCLUSIONS: The analysis of the DWI-APLS method showed a correlation between age and the ALPS index in second-degree distribution which peaked in the 40's generation. This finding in normal subjects may be fundamental in the analysis of disease cases. We tried to evaluate the glymphatic system status in a wide range of age groups using diffusion-weighted image analysis along the perivascular space (DWI-ALPS) method, and the results showed a correlation between age and the ALPS index in second-degree distribution which peaked in the 40's generation.

DOI： 10.1007/s11604-022-01275-0

人工知能を応用したバーチャル3D thin-section CTを用いた肺腺癌の充実成分径の計測 Reviewed

岩野信吾, 神谷晋一朗, 伊藤倫太郎, 工藤彰, 北村嘉郎, 中村圭児, 長縄慎二

断層映像研究会雑誌 Vol. 49 ( 2 ) page： 39 - 39 2022.9

Development of a high-resolution two-dimensional detector-based dose verification system for tumor-tracking irradiation in the CyberKnife system. Reviewed International journal

Fumitaka Kawabata, Takeshi Kamomae, Kuniyasu Okudaira, Masataka Komori, Hiroshi Oguchi, Motoharu Sasaki, Masaki Mori, Mariko Kawamura, Shinji Abe, Shunichi Ishihara, Shinji Naganawa

Journal of applied clinical medical physics Vol. 23 ( 8 ) page： e13645 - e13645 2022.8

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

We aim to evaluate the basic characteristics of SRS MapCHECK (SRSMC) for CyberKnife (CK) and establish a dose verification system using SRSMC for the tumor-tracking irradiation for CK. The field size and angular dependence of SRSMC were evaluated for basic characterization. The output factors (OPFs) and absolute doses measured by SRSMC were compared with those measured using microDiamond and microchamber detectors and those calculated by the treatment planning system (TPS). The angular dependence was evaluated by comparing the SRSMC with a microchamber. The tumor-tracking dose verification system consists of SRSMC and a moving platform. The doses measured using SRSMC were compared with the doses measured using a microchamber and radiochromic film. The OPFs and absolute doses of SRSMC were within ±3.0% error for almost all field sizes, and the angular dependence was within ±2.0% for all incidence angles. The absolute dose errors between SRSMC and TPS tended to increase when the field size was smaller than 10 mm. The absolute doses of the tumor-tracking irradiation measured using SRSMC and those measured using a microchamber agreed within 1.0%, and the gamma pass rates of SRSMC in comparison with those of the radiochromic film were greater than 95%. The basic characteristics of SRSMC for CK presented acceptable results for clinical use. The results of the tumor-tracking dose verification system realized using SRSMC were equivalent to those of conventional methods, and this system is expected to contribute toward improving the efficiency of quality control in many facilities.

DOI： 10.1002/acm2.13645

Contrast-Enhanced Fluid-Attenuated Inversion Recovery in Neuroimaging: A Narrative Review on Clinical Applications and Technical Advances. Reviewed International journal

Sung Jun Ahn, Toshiaki Taoka, Won-Jin Moon, Shinji Naganawa

Journal of magnetic resonance imaging : JMRI Vol. 56 ( 2 ) page： 341 - 353 2022.8

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

While contrast-enhanced fluid-attenuated inversion recovery (FLAIR) has long been regarded as an adjunct sequence to evaluate leptomeningeal disease in addition to contrast-enhanced T1-weighted imaging, it is gradually being used for more diverse pathologies beyond leptomeningeal disease. Contrast-enhanced FLAIR is known to be highly sensitive to low concentrations of gadolinium within the fluid. Accordingly, recent research has suggested the potential utility of contrast-enhanced FLAIR in various kinds of disease, such as Meniere's disease, seizure, stroke, traumatic brain injury, and brain metastasis, in addition to being used for visualizing glymphatic dysfunction. However, its potential applications have been reported sporadically in an unorganized manner. Furthermore, the exact mechanism for its superior sensitivity to low concentrations of gadolinium has not been fully understood. Rapidly developing magnetic resonance technology and unoptimized parameters for FLAIR may challenge its accurate application in clinical practice. This review provides the fundamental mechanism of contrast-enhanced FLAIR, systematically describes its current and potential clinical application, and elaborates on technical considerations for its optimization. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 5.

DOI： 10.1002/jmri.28117

The Incidence and Its Associated Factors Relevant to Brain Radionecrosis That Requires Intervention Following Single or Fractionated Stereotactic Radiosurgery Using Vero4DRT for Brain Metastases Reviewed

Takehiro Yamada, Kazuhiro Ohtakara, Takeshi Kamomae, Junji Itoh, Hideki Shimada, Shunichi Ishihara, Shinji Naganawa

CUREUS JOURNAL OF MEDICAL SCIENCE Vol. 14 ( 6 ) page： e25888 - e25888 2022.6

Embolization using patient-specific vascular models created by a 3D printer for difficult cases: a report of two cases. Reviewed Open Access

Tomohiro Komada, Takeshi Kamomae, Masaya Matsushima, Ryota Hyodo, Shinji Naganawa

Nagoya journal of medical science Vol. 84 ( 2 ) page： 477 - 483 2022.5

Language：English Publishing type：Research paper (scientific journal)

With the widespread use of three-dimensional printers, organ models created by these printers are now being used in the medical field for preoperative planning of surgeries. In this article, we report two cases in which embolization was expected to be difficult, and the three-dimensional printer-based vascular modeling was helpful in planning the surgery. The first case involved an aneurysm of the splenic artery. We attempted to embolize the aneurysm but were unable to advance the catheter into the distal artery and discontinued the procedure. The second case was a perianal varicose vein, which was initially treated with percutaneous transhepatic obliteration but was recanalized and required embolization. However, we expected difficulty in selecting the inferior mesenteric vein. In both cases, the vascular models were created using a 3D printer from the patients' computed tomography images. Preoperative planning, including treatment simulation, was based on these models. The time required to print a three-dimensional vascular model was approximately 12 hours at a cost of less than $10 each. Patient-specific vascular models using a three-dimensional printer can be a simple and inexpensive tool that can increase the success of embolization in difficult cases.

DOI： 10.18999/nagjms.84.2.477

Letter to editor on the article "A non-invasive, automated diagnosis of Menière's disease using radiomics and machine learning on conventional magnetic resonance imaging: a multicentric, case-controlled feasibility study" by van der Lubbe Mfja et al. Reviewed International journal

Shinji Naganawa, Rintaro Ito, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

La Radiologia medica Vol. 127 ( 4 ) page： 458 - 459 2022.4

Does the Pulsatile Non-uniform Flow Matter in MR Flowmetry? Reviewed

Masataka Sugiyama, Yasuo Takehara, Shinji Naganawa

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 21 ( 2 ) page： 365 - 371 2022.3

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

3D cine phase-contrast (4D flow) MRI is a sequence with great potential for non-invasive time-resolved 3D flowmetry at arbitrary vessel sections in various blood vessels. However, it is not widely known that the flowmetry with 4D flow MRI is vulnerable to pulsatile and non-uniform flow. Due to the limited spatial and temporal resolutions, averaging within the 3D voxel is occurring during the flowmetry. A simple solution is to avoid setting the measurement plane in the area where non-uniform flow is dominant, which is possible with an aid of streamline depictions generated by computational fluid dynamics (CFD) or 4D flow MRI data. Unlike 4D flow MRI, flowmetry in CFD simulation can use higher spatial and temporal resolution depending on computer performance; therefore, it is robust to fluctuating non-uniform flow. However, the performance of CFD simulations might be limited due to inlet conditions with low temporal resolution. Difficulty applying complex blood flow such as reflection flow from periphery may also limit accurate simulation. Caution should be taken when comparing the result of CFD simulation to that of 4D flow measurement.

DOI： 10.2463/mrms.rev.2021-0099

Hybrid 3D T1-weighted gradient-echo sequence for fiducial marker detection and tumor delineation via magnetic resonance imaging in liver stereotactic body radiation therapy. Reviewed International journal

Yutaka Kato, Takeshi Kamomae, Motoki Kumagai, Yumi Oie, Yumiko Noguchi, Kuniyasu Okudaira, Mariko Kawamura, Toshiaki Taoka, Shinji Naganawa

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Gold fiducial markers are used to guide liver stereotactic body radiation therapy (SBRT) and are hard to detect by magnetic resonance imaging (MRI). In this study, the parameters of the three-dimensional T1-weighted turbo gradient-echo (3D T1W-GRE) sequence were optimized for gold marker detection without degrading tumor delineation. METHODS: Custom-made phantoms mimicking tumor and normal liver parenchyma were prepared and embedded with a gold marker. The 3D T1W-GRE was scanned by varying echo time (TE), bandwidth (BW), flip angle (FA), and base matrix size. The signal-to-noise ratio (SNR), contrast ratio (CR), and relative standard deviation (RSD) of the signal intensity in the area including the gold marker were evaluated, and the parameters were optimized accordingly. The modified 3D T1W-GRE (called HYBRID) was compared with the conventional T1W-GRE- and T2*-sequences in both phantom and clinical studies. In the clinical study of six patients with primary liver tumors, two observers visually assessed marker detection, tumor delineation, and overall image quality on a four-point scale. RESULTS: In the phantom study, HYBRID showed significantly higher SNR and RSD than those of conventional T1W-GRE (P < 0.001). In the clinical study, HYBRID yielded significantly higher scores than conventional T1W-GRE did in terms of marker detection (P < 0.001). The scores of both sequences were not statistically different in terms of tumor delineation and overall image quality (P = 0.56 and P = 0.32). CONCLUSIONS: The proposed HYBRID sequence improved gold fiducial marker detection without degrading tumor delineation in MRI for SBRT of primary liver tumor.

DOI： 10.1016/j.ejmp.2022.01.003

歪みのないMRI拡散強調画像の放射線治療計画への臨床応用 Reviewed

加藤裕, 奥平訓康, 丸山克也, 田岡俊昭, 長縄慎二

日本放射線技術学会総会学術大会予稿集 Vol. 78回 page： 169 - 169 2022.3

17O標識水と市販点眼薬の画像化に向けた初期検討 Ultra-heavily T2強調画像の可能性 Invited

加藤裕, 山口博司, 田岡俊昭, 長縄慎二

日本放射線技術学会総会学術大会予稿集 Vol. 78回 page： 190 - 190 2022.3

コークスクリュー型高速パラレルイメージング併用3D-FLAIRシーケンスの基礎的検討 Reviewed

加藤裕, 田岡俊昭, 丸山克也, 長縄慎二

日本放射線技術学会総会学術大会予稿集 Vol. 78回 page： 214 - 214 2022.3

Water Diffusivity Changes Along the Perivascular Space After Lumboperitoneal Shunt Surgery in Idiopathic Normal Pressure Hydrocephalus. Reviewed International journal

Junko Kikuta, Koji Kamagata, Toshiaki Taoka, Kaito Takabayashi, Wataru Uchida, Yuya Saito, Christina Andica, Akihiko Wada, Kaito Kawamura, Chihiro Akiba, Madoka Nakajima, Masakazu Miyajima, Shinji Naganawa, Shigeki Aoki

Frontiers in neurology Vol. 13 page： 843883 - 843883 2022.2

Language：English Publishing type：Research paper (scientific journal)

Background: The aim of this study was to evaluate the water diffusivity changes along the perivascular space after lumboperitoneal shunt (LPS) surgery in idiopathic normal pressure hydrocephalus. Methods: Nine patients diagnosed with idiopathic normal pressure hydrocephalus (iNPH; three men and six women, mean age ± SD = 75.22 ± 5.12 years) according to the guidelines for iNPH in Japan were included in the study. Post-LPS surgery, six patients with iNPH who exhibited improvement in symptoms were defined as responder subjects, while three patients with iNPH who did not were defined as non-responder subjects. We calculated the mean analysis along the perivascular space (ALPS) index of the left and right hemispheres and compared the differences between pre- and post-LPS surgery mean ALPS indices in iNPH patients. In the responder or non-responder subjects, the mean ALPS indices in the pre- and post-operative iNPH groups were compared using Wilcoxon signed-rank tests. Next, correlation analyses between pre- and post-operation changes in the mean ALPS index and clinical characteristics were conducted. Results: The mean ALPS index of the post-operative iNPH group was significantly higher than that of the pre-operative iNPH group (p = 0.021). In responder subjects, the mean ALPS index of the post-operative iNPH group was significantly higher than that of the pre-operative iNPH group (p = 0.046). On the other hand, in the non-responder subjects, the mean ALPS index of the post-operative iNPH group was not significantly different compared to the pre-operative iNPH group (p = 0.285). The mean ALPS index change was not significantly correlated with changes in the Mini-Mental State Examination (MMSE) score (r = -0.218, p = 0.574), Frontal Assessment Battery (FAB) score (r = 0.185, p = 0.634), Trail Making Test A (TMTA) score (r = 0.250, p = 0.516), and Evans' index (r = 0.109, p = 0.780). In responder subjects, the mean ALPS index change was significantly correlated with Evans' index in pre-operative patients with iNPH (r = 0.841, p = 0.036). Conclusion: This study demonstrates the improved water diffusivity along perivascular space in patients with iNPH after LPS surgery. This could be indicative of glymphatic function recovery following LPS surgery.

DOI： 10.3389/fneur.2022.843883

Reproducibility of diffusion tensor image analysis along the perivascular space (DTI-ALPS) for evaluating interstitial fluid diffusivity and glymphatic function: CHanges in Alps index on Multiple conditiON acquIsition eXperiment (CHAMONIX) study. Reviewed

中枢神経原発の成人T細胞白血病・リンパ腫の1例 Reviewed

長井尚哉, 川井恒, 田岡俊昭, 伊藤信嗣, 長縄慎二, 加賀谷裕介, 寺倉精太郎, 横井聡, 勝野雅央, 河野奨, 下山芳江

Japanese Journal of Radiology Vol. 40 ( Suppl. ) page： 25 - 25 2022.2

Toshiaki Taoka, Rintaro Ito, Rei Nakamichi, Koji Kamagata, Mayuko Sakai, Hisashi Kawai, Toshiki Nakane, Takashi Abe, Kazushige Ichikawa, Junko Kikuta, Shigeki Aoki, Shinji Naganawa

Japanese journal of radiology Vol. 40 ( 2 ) page： 147 - 158 2022.2

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The diffusion tensor image analysis along the perivascular space (DTI-ALPS) method was developed to evaluate the brain's glymphatic function or interstitial fluid dynamics. This study aimed to evaluate the reproducibility of the DTI-ALPS method and the effect of modifications in the imaging method and data evaluation. MATERIALS AND METHODS: Seven healthy volunteers were enrolled in this study. Image acquisition was performed for this test-retest study using a fixed imaging sequence and modified imaging methods which included the placement of region of interest (ROI), imaging plane, head position, averaging, number of motion-proving gradients, echo time (TE), and a different scanner. The ALPS-index values were evaluated for the change of conditions listed above. RESULTS: This test-retest study by a fixed imaging sequence showed very high reproducibility (intraclass coefficient = 0.828) for the ALPS-index value. The bilateral ROI placement showed higher reproducibility. The number of averaging and the difference of the scanner did not influence the ALPS-index values. However, modification of the imaging plane and head position impaired reproducibility, and the number of motion-proving gradients affected the ALPS-index value. The ALPS-index values from 12-axis DTI and 3-axis diffusion-weighted image (DWI) showed good correlation (r = 0.86). Also, a shorter TE resulted in a larger value of the ALPS-index. CONCLUSION: ALPS index was robust under the fixed imaging method even when different scanners were used. ALPS index was influenced by the imaging plane, the number of motion-proving gradient axes, and TE in the imaging sequence. These factors should be uniformed in the planning ALPS method studies. The possibility to develop a 3-axis DWI-ALPS method using three axes of the motion-proving gradient was also suggested.

DOI： 10.1007/s11604-021-01187-5

＜Editors' Choice＞ Evaluation of system-related magnetic resonance imaging geometric distortion in radiation therapy treatment planning: two approaches and effectiveness of three-dimensional distortion correction.

Yutaka Kato, Kuniyasu Okudaira, Takeshi Kamomae, Motoki Kumagai, Youta Nagai, Toshiaki Taoka, Yoshiyuki Itoh, Shinji Naganawa

Nagoya journal of medical science Vol. 84 ( 1 ) page： 29 - 41 2022.2

Language：English Publishing type：Research paper (scientific journal)

We propose two methods to evaluate system-related distortion in magnetic resonance imaging (MRI) in radiation therapy treatment planning (RTP) and demonstrate the importance of three-dimensional (3D) distortion correction (DC) by quantitatively measuring the distortion magnitude. First, a small pin phantom was scanned at multiple positions using an external laser guide for accurate phantom placement and combined into one image encompassing a large area. Direct plane images were used for evaluating in-plane distortion and multiplanar reconstruction images for through-plane distortion with no DC, two-dimensional (2D) DC, and 3D DC. Second, a large grid sheet was scanned as the direct plane of the phantom placement. The distortion magnitude was determined by measuring the displacement between the MRI and reference coordinates. The measured distortions were compared between in- and through-plane when applying DC and between the two methods. The small pin phantom method can be used to evaluate a wide range of distortions, whereas data from the entire plane can be obtained with a single scan using the grid sheet without a laser guide. The mean distortion magnitudes differed between the methods. Furthermore, the 3D DC reduced in- and through-plane distortions. In conclusion, the small pin phantom method can be used to evaluate a wide range of distortions by creating a combined image, whereas the grid sheet method is simpler, accurate, repeatable, and does not require a special-order phantom or laser guide. As 3D DC reduces both in- and through-plane distortions, it can be used to improve RTP quality.

DOI： 10.18999/nagjms.84.1.29

Features from MRI texture analysis associated with survival outcomes in triple-negative breast cancer patients. Reviewed

Labyrinthitis With Endolymphatic Hydrops Revealed by Imaging Analysis in a Case With Severe Postoperative Complications Following Stapes Surgery. Reviewed International journal

Masumi Kobayashi, Tadao Yoshida, Yasue Uchida, Satofumi Sugimoto, Shinji Naganawa, Michihiko Sone

Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology Vol. 43 ( 1 ) page： E134 - E136 2022.1

Saki Kamiya, Hiroko Satake, Yoko Hayashi, Satoko Ishigaki, Rintaro Ito, Mariko Kawamura, Toshiaki Taoka, Shingo Iwano, Shinji Naganawa

Breast cancer (Tokyo, Japan) Vol. 29 ( 1 ) page： 164 - 173 2022.1

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The purpose of the study is to evaluate the associations between intratumoral or peritumoral textural features derived from pretreatment magnetic resonance imaging (MRI) and recurrence-free survival (RFS) in triple-negative breast cancer (TNBC) patients. METHODS: Forty-three patients with TNBC who underwent preoperative MRI between February 2008 and March 2014 were included. We performed two-dimensional texture analysis on the intratumoral or peritumoral region of interest (ROI) on axial of T2-weighted image (T2WI), dynamic contrast-enhanced (DCE)-MRI and DCE-MRI subtraction images. We also analyzed histopathological data. Cox proportional hazards models were used to investigate associations with survival outcomes. RESULTS: Twelve of the 43 patients (27.9%) had recurrence disease, at a median of 32.5 months follow-up (1.4-61.5 months). In univariate analysis, nine texture features in T2WI and DCE-MRI subtraction images were significantly associated with RFS. In multivariate analysis, intratumoral difference entropy in DCE-MRI subtraction images in the initial phase (hazard ratio 11.71; 95% confidence interval (CI) [1.41, 97.00]; p value 0.023) and, peritumoral difference variance in DCE-MRI subtraction images in the delayed phase (hazard ratio 9.60; 95% CI [1.98, 46.51]; p value 0.005), were both independently associated with RFS. Moreover, multivariate analysis revealed the presence of lymphovascular invasion as independently associated with RFS (hazard ratio 8.13; 95% CI [2.16, 30.30]; p value 0.002). CONCLUSIONS: At pretreatment MRI, an intratumoral and peritumoral quantitative approach using texture analysis has the potential to serve as a prognostic marker in patients with TNBC.

DOI： 10.1007/s12282-021-01294-1

Radiomics in breast MRI: current progress toward clinical application in the era of artificial intelligence. Reviewed International journal

Hiroko Satake, Satoko Ishigaki, Rintaro Ito, Shinji Naganawa

La Radiologia medica Vol. 127 ( 1 ) page： 39 - 56 2022.1

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

Breast magnetic resonance imaging (MRI) is the most sensitive imaging modality for breast cancer diagnosis and is widely used clinically. Dynamic contrast-enhanced MRI is the basis for breast MRI, but ultrafast images, T2-weighted images, and diffusion-weighted images are also taken to improve the characteristics of the lesion. Such multiparametric MRI with numerous morphological and functional data poses new challenges to radiologists, and thus, new tools for reliable, reproducible, and high-volume quantitative assessments are warranted. In this context, radiomics, which is an emerging field of research involving the conversion of digital medical images into mineable data for clinical decision-making and outcome prediction, has been gaining ground in oncology. Recent development in artificial intelligence has promoted radiomics studies in various fields including breast cancer treatment and numerous studies have been conducted. However, radiomics has shown a translational gap in clinical practice, and many issues remain to be solved. In this review, we will outline the steps of radiomics workflow and investigate clinical application of radiomics focusing on breast MRI based on published literature, as well as current discussion about limitations and challenges in radiomics.

DOI： 10.1007/s11547-021-01423-y

Reserve and maintenance in the aging brain: A longitudinal study of healthy older adults. Reviewed International journal

Epifanio Bagarinao, Hirohisa Watanabe, Satoshi Maesawa, Kazuya Kawabata, Kazuhiro Hara, Reiko Ohdake, Aya Ogura, Daisuke Mori, Noritaka Yoneyama, Kazunori Imai, Takamasa Yokoi, Toshiyasu Kato, Shuji Koyama, Masahisa Katsuno, Toshihiko Wakabayashi, Masafumi Kuzuya, Minoru Hoshiyama, Haruo Isoda, Shinji Naganawa, Norio Ozaki, Gen Sobue

eNeuro Vol. 9 ( 1 ) page： 0455-21 - 0455-21 2022.1

Language：English Publishing type：Research paper (scientific journal)

The aging brain undergoes structural changes even in very healthy individuals. Quantifying these changes could help disentangle pathological changes from those associated with the normal human aging process. Using longitudinal MRI data from 227 carefully selected healthy human cohort with age ranging from 50 to 80 years old at baseline scan, we quantified age-related volumetric changes in the brain of healthy human older adults. Longitudinally, the rates of tissue loss in total gray matter (GM) and white matter were 2,497.5 mm3 per year and 2,579.8 mm3 per year, respectively. Across the whole brain, the rates of GM decline varied with regions in the frontal and parietal lobes having faster rates of decline, whereas some regions in the occipital and temporal lobes appeared relatively preserved. In contrast, cross sectional changes were mainly observed in the temporal-occipital regions. Similar longitudinal atrophic changes were also observed in subcortical regions including thalamus, hippocampus, putamen, and caudate, whereas the pallidum showed an increasing volume with age. Overall, regions maturing late in development (frontal, parietal) are more vulnerable to longitudinal decline, whereas those that fully mature in the early stage (temporal, occipital) are mainly affected by cross sectional changes in healthy older cohort. This may suggest that, for a successful healthy aging, the former needs to be maximally developed at an earlier age to compensate for the longitudinal decline later in life and the latter to remain relatively preserved even in old age, consistent with both concepts of reserve and brain maintenance.Significance StatementAging is associated with gray matter (GM) decline, yet some individuals tend to remain cognitively healthy even in advanced age. What differentiates the brains of "healthy agers" from those individuals who are prone to faster cognitive decline still remains unclear. Using longitudinal MRI data from a carefully selected cohort, we examined the brain aging characteristics of healthy agers. Our findings showed that, even in this population, frontal-parietal regions have faster longitudinal rate of GM decline, whereas some temporal-occipital regions appeared relatively preserved. These findings may suggest that, for a successful healthy aging, frontal-parietal regions need to be maximally developed to compensate for the longitudinal decline later in life and the temporal-occipital regions to remain relatively preserved even in old age.

DOI： 10.1523/ENEURO.0455-21.2022

An Investigation of Water Diffusivity Changes along the Perivascular Space in Elderly Subjects with Hypertension Reviewed

J. Kikuta, K. Kamagata, K. Takabayashi, T. Taoka, H. Yokota, C. Andica, A. Wada, Y. Someya, Y. Tamura, R. Kawamori, H. Watada, S. Naganawa, S. Aoki

American Journal of Neuroradiology Vol. 43 ( 1 ) page： 48 - 55 2022.1

The Glymphatic System: A Review of the Challenges in Visualizing its Structure and Function with MR Imaging. Reviewed

Shinji Naganawa, Toshiaki Taoka

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 21 ( 1 ) page： 182 - 194 2022

Authorship：Lead author,　Last author Language：English Publishing type：Research paper (scientific journal)

The central nervous system (CNS) was previously thought to be the only organ system lacking lymphatic vessels to remove waste products from the interstitial space. Recently, based on the results from animal experiments, the glymphatic system was hypothesized. In this hypothesis, cerebrospinal fluid (CSF) enters the periarterial spaces, enters the interstitial space of the brain parenchyma via aquaporin-4 (AQP4) channels in the astrocyte end feet, and then exits through the perivenous space, thereby clearing waste products. From the perivenous space, the interstitial fluid drains into the subarachnoid space and meningeal lymphatics of the parasagittal dura. It has been reported that the glymphatic system is particularly active during sleep. Impairment of glymphatic system function might be a cause of various neurodegenerative diseases such as Alzheimer's disease, normal pressure hydrocephalus, glaucoma, and others. Meningeal lymphatics regulate immunity in the CNS. Many researchers have attempted to visualize the function and structure of the glymphatic system and meningeal lymphatics in vivo using MR imaging. In this review, we aim to summarize these in vivo MR imaging studies and discuss the significance, current limitations, and future directions. We also discuss the significance of the perivenous cyst formation along the superior sagittal sinus, which is recently discovered in the downstream of the glymphatic system.

DOI： 10.2463/mrms.rev.2020-0122

Cross-sectional Area of the Superior Petrosal Sinus is Reduced in Patients with Significant Endolymphatic Hydrops. Reviewed

Shinji Naganawa, Rintaro Ito, Hisashi Kawai, Mariko Kawamura, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 21 ( 3 ) page： 459 - 467 2022

Authorship：Lead author,　Last author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: To evaluate the relationship between the size of the venous structures related to the inner ear and the degree of endolymphatic hydrops (EH). METHODS: Thirty-four patients with a suspicion of EH underwent whole brain MR imaging including the inner ear. Images were obtained pre- and post-administration, and at 4 and 24 hours after the intravenous administration of a gadolinium-based contrast agent (IV-GBCA). The cross-sectional areas (CSA) of the internal jugular vein (IJV), superior petrosal sinus (SPS), and inferior petrosal sinus (IPS) were measured on the magnetization prepared rapid acquisition of gradient echo (MPRAGE) images obtained immediately after the IV-GBCA. The grade of EH was determined on the hybrid of reversed image of positive endolymph signal and native image of positive perilymph signal (HYDROPS) images obtained at 4 hours after IV-GBCA as no, mild, and significant EH according to the previously proposed grading system for the cochlea and vestibule, respectively. The ipsilateral CSA was compared between groups with each level of EH grade. P < 0.05 was considered statistically significant. RESULTS: There were no statistically significant differences between EH grades for the CSA of the IJV or that of the IPS in either the cochlea or the vestibule. The CSA of the SPS in the groups with significant EH was significantly smaller than that in the group with no EH, for both the cochlea (P < 0.01) and the vestibule (P < 0.05). In an ROC analysis to predict significant EH, the cut-off CSA value in the SPS was 3.905 mm2 for the cochlea (AUC: 0.8762, 95% confidence interval [CI]: 0.7952‒0.9572) and 3.805 mm2 for the vestibule (AUC: 0.7727, 95% CI: 0.6539‒0.8916). CONCLUSION: In the ears with significant EH in the cochlea or vestibule, the CSA of the ipsilateral SPS was smaller than in the ears without EH.

DOI： 10.2463/mrms.mp.2021-0010

MR Imaging of Endolymphatic Hydrops in Five Minutes. Reviewed

Shinji Naganawa, Rintaro Ito, Hisashi Kawai, Mariko Kawamura, Toshiaki Taoka, Mayuko Sakai, Kazushige Ichikawa, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 21 ( 3 ) page： 401 - 405 2022

Authorship：Lead author,　Last author Language：English Publishing type：Research paper (scientific journal)

In this study, we present images acquired by a fast-imaging method for the evaluation of endolymphatic hydrops after intravenous administration of a single dose of gadolinium-based contrast agent. We utilized the hybrid of reversed image of MR cisternography and a positive perilymph signal by heavily T2- weighted 3D-fluid attenuated inversion recovery-multiplied by T2 (HYDROPS2-Mi2) method combined with deep learning reconstruction denoising. The scan time for the fast protocol was approximately 5 mins, which is far shorter than previously reported scan times. The fast acquisition provides similar image quality and less motion artifacts compared to the longer method.

DOI： 10.2463/mrms.ici.2021-0022

Effects of Head Motion on the Evaluation of Age-related Brain Network Changes Using Resting State Functional MRI. Reviewed

Sanae Kato, Epifanio Bagarinao, Haruo Isoda, Shuji Koyama, Hirohisa Watanabe, Satoshi Maesawa, Daisuke Mori, Kazuhiro Hara, Masahisa Katsuno, Minoru Hoshiyama, Shinji Naganawa, Norio Ozaki, Gen Sobue

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 20 ( 4 ) page： 338 - 346 2021.12

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The estimation of functional connectivity (FC) measures using resting state functional MRI (fMRI) is often affected by head motion during functional imaging scans. Head motion is more common in the elderly than in young participants and could therefore affect the evaluation of age-related changes in brain networks. Thus, this study aimed to investigate the influence of head motion in FC estimation when evaluating age-related changes in brain networks. METHODS: This study involved 132 healthy volunteers divided into 3 groups: elderly participants with high motion (OldHM, mean age (±SD) = 69.6 (±5.31), N = 44), elderly participants with low motion (OldLM, mean age (±SD) = 68.7 (±4.59), N = 43), and young adult participants with low motion (YugLM, mean age (±SD) = 27.6 (±5.26), N = 45). Head motion was quantified using the mean of the framewise displacement of resting state fMRI data. After preprocessing all resting state fMRI datasets, several resting state networks (RSNs) were extracted using independent component analysis (ICA). In addition, several network metrics were also calculated using network analysis. These FC measures were then compared among the 3 groups. RESULTS: In ICA, the number of voxels with significant differences in RSNs was higher in YugLM vs. OldLM comparison than in YugLM vs. OldHM. In network analysis, all network metrics showed significant (P < 0.05) differences in comparisons involving low vs. high motion groups (OldHM vs. OldLM and OldHM vs. YugLM). However, there was no significant (P > 0.05) difference in the comparison involving the low motion groups (OldLM vs. YugLM). CONCLUSION: Our findings showed that head motion during functional imaging could significantly affect the evaluation of age-related brain network changes using resting state fMRI data.

DOI： 10.2463/mrms.mp.2020-0081

Evaluating the Effect of Arterial Pulsation on Cerebrospinal Fluid Motion in the Sylvian Fissure of Patients with Middle Cerebral Artery Occlusion Using Low b-value Diffusion-weighted Imaging Reviewed

Toshiaki Taoka, Hisashi Kawai, Toshiki Nakane, Takashi Abe, Rei Nakamichi, Rintaro Ito, Yutaro Sasaki, Ayumi Nishida, Shinji Naganawa

Magnetic Resonance in Medical Sciences Vol. 20 ( 4 ) page： 371 - 377 2021.12

Incidental findings on computed tomography for preoperative assessment before transcatheter aortic valve implantation in Japanese patients. Reviewed

Akihiro Tobe, Akihito Tanaka, Yoshiyuki Tokuda, Yusuke Miki, Kenji Furusawa, Sho Akita, Taro Fujii, Yoshinori Tsutsumi, Hideki Ishii, Shingo Iwano, Shinji Naganawa, Akihiko Usui, Toyoaki Murohara

Heart and vessels Vol. 36 ( 12 ) page： 1911 - 1922 2021.12

Language：English Publishing type：Research paper (scientific journal)

Extra-cardiovascular incidental findings (IFs) on preoperative computed tomography (CT) are frequently observed in transcatheter aortic valve implantation (TAVI) candidates. However, the backgrounds of TAVI candidates and comorbidities differ based on the race and/or country, and data on IFs in a specific population are not always applicable to another. The aim of this study was to assess the prevalence, type, and clinical impact of IFs in Japanese TAVI candidates. This was a retrospective, single-center, observational study. CT reports of 257 TAVI candidates were reviewed, and IFs were classified as (a) insignificant: findings that did not require further investigation, treatment, or follow-up; (b) intermediate: findings that needed to be followed up or were considered for further investigation but did not affect the planning of TAVI; and (c) significant: findings that required further investigation immediately or affected the planning of TAVI. At least one IF was found in 254 patients (98.8%). Insignificant, intermediate, and significant IFs were found in 253 (98.4%), 153 (59.5%), and 34 (13.2%) patients, respectively. Newly indicated significant IFs were found in 19 patients (7.4%). In 2 patients (0.8%), TAVI was canceled because of significant IFs. In patients who consequently underwent TAVI, the presence of significant IFs was not associated with the duration from CT performance to TAVI [28 (19-40) days vs. 27 (19-43) days, p = 0.74] and all-cause mortality during the median follow-up period of 413 (223-805) days (p = 0.44). Almost all Japanese TAVI candidates had at least one IF, and the prevalence of significant IFs was not negligible. Although the presence of significant IFs was not associated with mid-term mortality, appropriate management of IFs was considered important.

DOI： 10.1007/s00380-021-01875-2

FLUID study: study protocol for an open-label, single-centre pilot study to investigate the efFect of Lemborexant on sleep management in Japanese sUbjects aged 50 years and older with Insomnia Disorder. Reviewed International journal

Ippei Okada, Kunihiro Iwamoto, Seiko Miyata, Akihiro Fujimoto, Masaki Tanaka, Manabu Amano, Nao Matsuyama, Toshiaki Taoka, Shinji Naganawa, Norio Ozaki

BMJ open Vol. 11 ( 11 ) page： e054885 2021.11

Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: Bidirectional associations have been reported between sleep disturbance and both cognitive impairment, including Alzheimer's disease and amyloid beta-peptide (Aβ) accumulation. These relationships can be explained by the glymphatic system, which acts as a garbage drainage system in the brain. As interstitial fluid dynamics are suggested to increase during sleep, clearance of Aβ can be influenced by sleep disturbance or deprivation. We hypothesised that using lemborexant, an orexin receptor antagonist, to improve sleep quality would also improve the function of the glymphatic system. We plan to examine the effect of lemborexant on sleep quality and the glymphatic system among patients with insomnia disorder. METHODS AND ANALYSIS: This pilot study is designed as an open-label, single-arm, single-centre trial. Thirty patients aged 50 years and over with insomnia will be recruited. The participants will take lemborexant (5 mg) at bedtime for 12 weeks and undergo a home-based sleep study at baseline and weeks 4 and 12, as well as MRI examinations to evaluate the glymphatic system at baseline and week 12. The primary outcome will be changes in objective sleep parameters as evaluated using a sleep monitoring system. The secondary outcomes will be changes in subjective sleep parameters. The relationships between changes in sleep parameters and the glymphatic system will be evaluated using diffusion tensor image analysis along the perivascular space, which is called the ALPS-index. Sleep parameters and the ALPS-index will be analysed using a paired t-test or Pearson's correlation coefficient. ETHICS AND DISSEMINATION: The study protocol was approved by Nagoya University Certified Review Board. The findings from this research will be published in peer-reviewed journals and be presented at local, national and international conferences. TRIAL REGISTRATION NUMBER: jRCTs041210024.

DOI： 10.1136/bmjopen-2021-054885

Development of an x-ray-opaque-marker system for quantitative phantom positioning in patient-specific quality assurance Reviewed

Kentaro Suzuki, Takeshi Kamomae, Hiroshi Oguchi, Fumitaka Kawabata, Kazuma Sugita, Kuniyasu Okudaira, Masaki Mori, Shinji Abe, Masataka Komori, Mariko Kawamura, Kazuhiro Ohtakara, Yoshiyuki Itoh, Shinji Naganawa

Physica Medica Vol. 91 page： 121 - 130 2021.11

A case of intraductal tubulopapillary neoplasm of the pancreas originating from the branch duct: cast in the mold sign. Reviewed Open Access

Ryota Horiguchi, Hiroshi Ogawa, Naoya Nagai, Yasuo Takehara, Shinji Naganawa, Yukihiro Yokoyama, Yoshie Shimoyama

Nagoya journal of medical science Vol. 83 ( 4 ) page： 869 - 875 2021.11

Language：English Publishing type：Research paper (scientific journal)

A 59-year-old man with jaundice and lower common bile duct stenosis was referred to our institution for diagnosis and treatment. Computed tomography and magnetic resonance imaging showed a well-circumscribed smoothly marginated solid mass lesion in the pancreatic head. He underwent pyloric preserving pancreatoduodenectomy. Histopathological specimen revealed that the mass was located in the dilated branch duct of the pancreatic head, and an intraductal tubulopapillary neoplasm originating from the branch pancreatic duct was diagnosed. On magnetic resonance cholangiopancreatography, the mass within the dilated duct branch in the pancreatic head was similar to a "cast in the mold" image, which we retrospectively deemed, might be reflecting the nature of this tumor.

DOI： 10.18999/nagjms.83.4.869

Bridging large-scale cortical networks: Integrative and function-specific hubs in the thalamus. Reviewed International journal

Kazuya Kawabata, Epifanio Bagarinao, Hirohisa Watanabe, Satoshi Maesawa, Daisuke Mori, Kazuhiro Hara, Reiko Ohdake, Michihito Masuda, Aya Ogura, Toshiyasu Kato, Shuji Koyama, Masahisa Katsuno, Toshihiko Wakabayashi, Masafumi Kuzuya, Minoru Hoshiyama, Haruo Isoda, Shinji Naganawa, Norio Ozaki, Gen Sobue

iScience Vol. 24 ( 10 ) page： 103106 - 103106 2021.10

Language：English Publishing type：Research paper (scientific journal)

The thalamus is critical for the brain's integrative hub functions; however, the localization and characterization of the different thalamic hubs remain unclear. Using a voxel-level network measure called functional connectivity overlap ratio (FCOR), we examined the thalamus' association with large-scale resting-state networks (RSNs) to elucidate its connector hub roles. Connections to the core-neurocognitive networks were localized in the anterior and medial parts, such as the anteroventral and mediodorsal nuclei areas. Regions functionally connected to the sensorimotor network were distinctively located around the lateral pulvinar nucleus but to a limited extent. Prominent connector hubs include the anteroventral, ventral lateral, and mediodorsal nuclei with functional connections to multiple RSNs. These findings suggest that the thalamus, with extensive connections to most of the RSNs, is well placed as a critical integrative functional hub and could play an important role for functional integration facilitating brain functions associated with primary processing and higher cognition.

DOI： 10.1016/j.isci.2021.103106

Magnetic resonance cisternography imaging findings related to the leakage of Gadolinium into the subarachnoid space Reviewed

Rei Nakamichi, Toshiaki Taoka, Hisashi Kawai, Tadao Yoshida, Michihiko Sone, Shinji Naganawa

Japanese Journal of Radiology Vol. 39 ( 10 ) page： 927 - 937 2021.10

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

<title>Abstract</title><sec>
<title>Purpose</title>
To identify magnetic resonance cisternography (MRC) imaging findings related to Gadolinium-based contrast agent (GBCA) leakage into the subarachnoid space.

</sec><sec>
<title>Materials and methods</title>
The number of voxels of GBCA leakage (V-leak) on 3D-real inversion recovery images was measured in 56 patients scanned 4 h post-intravenous GBCA injection. Bridging veins (BVs) were identified on MRC. The numbers of BVs with surrounding cystic structures (BV-cyst), with arachnoid granulations protruding into the superior sagittal sinus (BV-AG-SSS) and the skull (BV-AG-skull), and including any of these factors (BV-incl) were recorded. Correlations between these variables and V-leak were examined based on the Spearman’s rank correlation coefficient. Receiver-operating characteristic (ROC) curves were generated to investigate the predictive performance of GBCA leakage.

</sec><sec>
<title>Results</title>
V-leak and the number of BV-incl were strongly correlated (<italic>r</italic> = 0.609, <italic>p</italic> < 0.0001). The numbers of BV-cyst and BV-AG-skull had weaker correlations with V-leak (<italic>r</italic> = 0.364, <italic>p</italic> = 0.006; <italic>r</italic> = 0.311, <italic>p</italic> = 0.020, respectively). The number of BV-AG-SSS was not correlated with V-leak. The ROC curve for contrast leakage exceeding 1000 voxels and the number of BV-incl had moderate accuracy, with an area under the curve of 0.871.

</sec><sec>
<title>Conclusion</title>
The number of BV-incl may be a predictor of GBCA leakage and a biomarker for waste drainage function without using GBCA.

</sec>

DOI： 10.1007/s11604-021-01137-1

Imaging diagnosis of autoimmune pancreatitis: computed tomography and magnetic resonance imaging. Reviewed

Other Link： https://link.springer.com/article/10.1007/s11604-021-01137-1/fulltext.html

Hiroshi Ogawa, Yasuo Takehara, Shinji Naganawa

Journal of medical ultrasonics (2001) Vol. 48 ( 4 ) page： 565 - 571 2021.10

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

Autoimmune pancreatitis (AIP) is a pancreatic phenotype of IgG4-related systemic disease. Since its first description in the literature, characteristic imaging features have gradually become known to many clinicians encompassing various specialties in the past quarter century. CT and MRI have been the workhorses for imaging diagnosis of AIP. Typical features include sausage-like swelling of the focal or entire pancreas, duct-penetrating sign, a capsule-like rim of the affected lesions, and homogeneous delayed enhancement or enhanced duct sign after contrast administration, as well as characteristic combined findings reflecting coexisting pathologies in the other organs as a systemic disease. In this review, recent and future developments in CT and MRI that may help diagnose AIP are discussed, including restricted diffusion and perfusion and increased elasticity measured using MR.

DOI： 10.1007/s10396-021-01145-8

The importance of choosing the right strategy to treat small cell carcinoma of the cervix: a comparative analysis of treatments. Reviewed International journal

Mariko Kawamura, Yutaro Koide, Taro Murai, Shunichi Ishihara, Yuuki Takase, Takayuki Murao, Dai Okazaki, Takahiro Yamaguchi, Kaoru Uchiyama, Yoshiyuki Itoh, Takeshi Kodaira, Yuta Shibamoto, Mika Mizuno, Fumitaka Kikkawa, Shinji Naganawa

BMC cancer Vol. 21 ( 1 ) page： 1046 - 1046 2021.9

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Standard treatments for small cell carcinoma of the cervix (SCCC) have not been established. In this study, we aimed to estimate the optimal treatment strategy for SCCC. METHODS: This was a multicenter retrospective study. Medical records of patients with pathologically proven SCCC treated between 2003 and 2016 were retrospectively analyzed. Overall survival (OS) was plotted using the Kaplan-Meier method. Log-rank tests and Cox regression analysis were used to assess the differences in survival according to stage, treatment strategy, and chemotherapy regimen. RESULTS: Data of 78 patients were collected, and after excluding patients without immunohistopathological staining, 65 patients were evaluated. The median age of the included patients was 47 (range: 24-83) years. The numbers of patients with International Federation of Gynecology and Obstetrics (FIGO) 2018 stages I-IIA, IIB-IVA, IVB were 23 (35%), 34 (52%), and 8 (12%), respectively. Of 53 patients who had undergone chemotherapy, 35 and 18 received SCCC and non-SCCC regimens as their first-line chemotherapy regimen, respectively. The 5-year OS for all patients was 49%, while for patients with FIGO stages I-IIA, IIB-IVA, IVB, it was 60, 50, and 0%, respectively. The 5-year OS rates for patients who underwent treatment with SCCC versus non-SCCC regimens were 59 and 13% (p < 0.01), respectively. This trend was pronounced in locally advanced stages. Multivariate analysis showed that FIGO IVB at initial diagnosis was a significant prognostic factor in all patients. Among the 53 patients who received chemotherapy, the SCCC regimen was associated with significantly better 5-year OS in both the uni- and multivariate analyses. CONCLUSION: Our results suggest that the application of an SCCC regimen such as EP or IP as first-line chemotherapy for patients with locally advanced SCCC may play a key role in OS. These findings need to be validated in future nationwide, prospective clinical studies.

DOI： 10.1186/s12885-021-08772-x

Changes in Vessel Wall Enhancement Related to the Recent Neurological Symptoms in Patients with Moyamoya Disease. Reviewed

Shinsuke Muraoka, Toshiaki Taoka, Hisashi Kawai, Sho Okamoto, Kenji Uda, Shinji Naganawa, Yoshio Araki

Neurologia medico-chirurgica Vol. 61 ( 9 ) page： 515 - 520 2021.9

Language：English Publishing type：Research paper (scientific journal)

Moyamoya disease (MMD) causes intracranial arterial stenosis progression. The progression of intracranial arterial stenosis will increase the risk of ischemic cerebrovascular events. This study aims to investigate the relationship between intracranial arterial stenosis progression, vessel wall enhancement (VWE), and the recent neurological symptoms. A total of 39 MMD patients (12 male; 37.6 ± 18.0 years old) were registered in this study analysis between April 2016 and July 2018. All patients received MRI at registration and 6, 12, and 24 months post-registration. The incidence of ischemic cerebrovascular events (transit ischemic attacks or cerebral infarction) was checked until December 2018. We evaluated the relationship between the intensity of VWE, intracranial arterial stenosis, and the recent neurological symptoms. During the mean follow-up period of 13.8 ± 5.5 months, the changes in VWE were observed in 33 hemispheres (42.3%), stenosis progression was observed in 21 hemispheres (26.9%), and recent neurological symptoms occurred in 10 hemispheres (12.8%). Stenosis progression was observed in 11 hemispheres (33.3%) in the VWE(+) group and ten hemispheres (22.2%) in the VWE(-) group (p = 0.310). The recent neurological symptoms were observed in eight hemispheres (21.2%) in the VWE(+) group and two hemispheres (4.44%) in the VWE(-) group (odds ratio 6.88, 95% confidence interval 1.35-34.98, p = 0.015). The intensity of VWE sometimes changes. The changes in VWE were significantly associated with the recent neurological symptoms but not with stenosis progression.

DOI： 10.2176/nmc.oa.2021-0058

Evaluation of the blood-perilymph barrier in ears with endolymphatic hydrops. Reviewed International journal

Tadao Yoshida, Masumi Kobayashi, Satofumi Sugimoto, Masaaki Teranishi, Shinji Naganawa, Michihiko Sone

Acta oto-laryngologica Vol. 141 ( 8 ) page： 736 - 741 2021.8

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Otological diseases including Meniere's disease (MD) involve endolymphatic hydrops (EH), which can be visualized by magnetic resonance imaging (MRI) with gadolinium contrast agents, but the temporal changes of contrast in the inner ear have not been evaluated. OBJECTIVES: We investigated the permeability of the blood-perilymph barrier (BPB) in ears with EH to evaluate the severity of the inner ear disturbances. MATERIALS AND METHODS: The study included 32 ears from 16 patients with EH or related diseases who underwent MRI. The permeability of the BPB was assessed by the signal-intensity ratio (SIR) at four-time points: before and at 10 min, 4 h, and 24 h after administration of gadolinium for assessing EH. RESULTS: Cochlear EH was found in 25 of the 32 ears, and vestibular EH in 11. The rate of EH was significantly higher in symptomatic ears; however, the existence of EH was not related to SIR values. Nevertheless, SIR values in the basal turn were significantly higher 4 and 24 h after injection of gadolinium in patients aged ≥50 years. CONCLUSION AND SIGNIFICANCE: Higher SIR values observed in older patients with EH indicate severe disturbances of the BPB in the cochlea, which may account for intractable inner ear disturbances in older patients.

DOI： 10.1080/00016489.2021.1957500

Dilatation of the Endolymphatic Space in the Ampulla of the Posterior Semicircular Canal: A New Clinical Finding Detected on Magnetic Resonance Imaging. Reviewed International journal

Masaru Morioka, Satofumi Sugimoto, Tadao Yoshida, Masaaki Teranishi, Masumi Kobayashi, Naoki Nishio, Naomi Katayama, Shinji Naganawa, Michihiko Sone

Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology Vol. 42 ( 6 ) page： E643 - E647 2021.7

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVES: To investigate the clinical features of ears with dilatation of the endolymphatic space in the ampulla of the posterior semicircular canal on magnetic resonance imaging. STUDY DESIGN: Retrospective study. SETTING: A university hospital. METHODS: This study included 1,842 ears from 934 patients who underwent 3-T magnetic resonance imaging with gadolinium to investigate the presence of endolymphatic hydrops. Age, sex distribution, hearing thresholds on pure-tone audiometry, and vestibular symptoms were compared between cases of unilateral and bilateral dilatation of the endolymphatic space in the ampulla of the posterior semicircular canal. RESULTS: Forty-eight ears (17 men and 14 women; mean age 49.9 yrs) showed dilatation of the endolymphatic space in the ampulla of the posterior semicircular canal. Age and the rate of chronic sensorineural hearing loss were significantly higher in the unilateral group (14 ears) than in the bilateral group (34 ears). The average hearing thresholds and rates of vestibular symptoms reported did not differ between unilateral and bilateral cases, but some patients showed positional nystagmus. CONCLUSIONS: Dilatation of the endolymphatic space in the ampulla was observed selectively in the posterior semicircular canal, though its pathogenesis was not clear. Such dilatation is not usually accompanied by vestibular endolymphatic hydrops, and it may be a cause of vertigo and dizziness.

DOI： 10.1097/MAO.0000000000003073

【COVID-19肺炎と肺疾患AI開発のフロントライン】COVID-19肺炎におけるAI研究の動向および問題点について Reviewed

伊藤倫太郎, 岩野信吾, 長縄慎二

医用画像情報学会雑誌 Vol. 38 ( 2 ) page： 32 - 40 2021.7

Authorship：Last author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：医用画像情報学会

COVID-19が世界中に広まり、COVID-19肺炎の診断に胸部CTや胸部単純X線の有用性が報告され、この画像所見を用いたAI開発が初期の段階から積極的に行われた。高性能なAIが多数存在するが、臨床において用いる際には注意すべき点が複数存在する。COVID-19肺炎に対して開発・使用された画像診断に関連するAI研究について、PubMedに2020年12月までに登録されたものを抽出しレビューを行った。

Novel Magnetic Resonance Imaging-Based Method for Accurate Diagnosis of Meniere's Disease Reviewed

Taeko Ito, Takashi Inoue, Hiroshi Inui, Toshiteru Miyasaka, Toshiaki Yamanaka, Kimihiko Kichikawa, Noriaki Takeda, Masato Kasahara, Tadashi Kitahara, Shinji Naganawa

Frontiers in Surgery Vol. 8 page： 671624 2021.6

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：Frontiers Media SA

Background: Pathologically, Meniere's disease symptoms are considered to be associated with endolymphatic hydrops. Examinations revealing endolymphatic hydrops can be useful for accurate Meniere's disease diagnosis. We previously reported a quantitative method for evaluating endolymphatic hydrops, i.e., by measuring the volume of the endolymphatic space using three-dimensional magnetic resonance imaging (MRI) of the inner ear. This study aimed to confirm the usefulness of our methods for diagnosing Meniere's disease. Here, we extracted new explanatory factors for diagnosing Meniere's disease by comparing the volume of the endolymphatic space between healthy volunteers and patients with Meniere's disease. Additionally, we validated our method by comparing its diagnostic accuracy with that of the conventional method.

Methods and Findings: This is a prospective diagnostic accuracy study performed at vertigo/dizziness centre of our university hospital, a tertiary hospital. Eighty-six patients with definite unilateral Meniere's disease and 47 healthy volunteers (25 and 33 males, and 22 and 53 females in the control and patient groups, respectively) were enrolled. All participants underwent 3-Tesla MRI 4 h after intravenous injection of gadolinium to reveal the endolymphatic space. The volume of the endolymphatic space was measured and a model for Meniere's disease diagnosis was constructed and compared with models using conventional criteria to confirm the effectiveness of the methods used. The area under the receiver operating characteristic curve of the method proposed in this study was excellent (0.924), and significantly higher than that derived using the conventional criteria (0.877). The four indices, sensitivity, specificity, positive predictive value, and negative predictive value, were given at the threshold; all of these indices achieved higher scores for the 3D model compared to the 2D model. Cross-validation of the models revealed that the improvement was due to the incorporation of the semi-circular canals.

Conclusions: Our method showed high diagnostic accuracy for Meniere's disease. Additionally, we revealed the importance of observing the semi-circular canals for Meniere's disease diagnosis. The proposed method can contribute toward providing effective symptomatic relief in Meniere's disease.

DOI： 10.3389/fsurg.2021.671624

Age estimates from brain magnetic resonance images of children younger than two years of age using deep learning. Reviewed International journal

Masahiro Kawaguchi, Hiroyuki Kidokoro, Rintaro Ito, Anna Shiraki, Takeshi Suzuki, Yuki Maki, Masaharu Tanaka, Yoko Sakaguchi, Hiroyuki Yamamoto, Yosiyuki Takahashi, Shinji Naganawa, Jun Natsume

Magnetic resonance imaging Vol. 79 page： 38 - 44 2021.6

Language：English Publishing type：Research paper (scientific journal)

The accuracy of brain age estimates from magnetic resonance (MR) images has improved with the advent of deep learning artificial intelligence (AI) models. However, most previous studies on predicting age emphasized aging from childhood to adulthood and old age, and few studies have focused on early brain development in children younger than 2 years of age. Here, we performed brain age estimates based on MR images in children younger than 2 years of age using deep learning. Our AI model, developed with one slice each of raw T1- and T2-weighted images from each subject, estimated brain age with a mean absolute error of 8.2 weeks (1.9 months). The estimates of our AI model were close to those of human specialists. The AI model also estimated the brain age of subjects with a myelination delay as significantly younger than the chronological age. These results indicate that the prediction accuracy of our AI model approached that of human specialists and that our simple method requiring less data and preprocessing facilitates a radiological assessment of brain development, such as monitoring maturational changes in myelination.

DOI： 10.1016/j.mri.2021.03.004

Dosimetric impacts of beam-hardening filter removal for the CyberKnife system Reviewed International journal Open Access

Takeshi Kamomae, Takuma Matsunaga, Junji Suzuki, Kuniyasu Okudaira, Fumitaka Kawabata, Yutaka Kato, Hiroshi Oguchi, Morihito Shimizu, Motoharu Sasaki, Yuki Takase, Mariko Kawamura, Kazuhiro Ohtakara, Yoshiyuki Itoh, Shinji Naganawa

PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS Vol. 86 page： 98 - 105 2021.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

Purpose: Equipment refurbishment was performed to remove the beam-hardening filter (BHF) from the CyberKnife system (CK). This study aimed to confirm the change in the beam characteristics between the conventional CK (present-BHF CK) and CK after the BHF was removed (absent-BHF CK) and evaluate the impact of BHF removal on the beam quality correction factors kQ. Methods: The experimental measurements of the beam characteristics of the present- and absent-BHF CKs were compared. The CKs were modeled using Monte Carlo simulations (MCs). The energy fluence spectra were calculated using MCs. Finally, kQ were estimated by combining the MC results and analytic calculations based on the TRS-398 and TRS-483 approaches. Results: All gamma values for percent depth doses and beam profiles between each CK were less than 0.5 following the 3%/1 mm criteria. The percentage differences for tissue-phantom ratios at depths of 20 and 10 cm and percentage depth doses at 10 cm between each CK were -1.20% and -0.97%, respectively. The MC results demonstrated that the photon energy fluence spectrum of the absent-BHF CK was softer than that of the presentBHF CK. The kQ values for the absent-BHF CK were in agreement within 0.02% with those for the present-BHF CK. Conclusions: The photon energy fluence spectrum was softened by the removal of BHF. However, no remarkable impact was observed for the measured beam characteristics and kQ. Therefore, the previous findings of the kQ values for the present-BHF CK can be directly used for the absent-BHF CK.

DOI： 10.1016/j.ejmp.2021.05.011

Toshio Ohashi, Shinji Naganawa, Saeko Iwata, Kayao Kuno

Japanese Journal of Radiology Vol. 39 ( 5 ) page： 433 - 441 2021.5

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Japan

Purpose: The purpose of this retrospective study was to investigate the relationship between age and leakage of intravenously administered gadolinium-based contrast agents (GBCAs) into the cerebrospinal fluid (CSF) by volumetric segmentation of the whole-cranium CSF. Materials and methods: In 30 patients clinically diagnosed with suspected endolymphatic hydrops, the three-dimensional real inversion recovery (3D-real IR) images were obtained at pre- and 4 h post-intravenous administration of a single dose of GBCA. The volume of interest was set on the whole-cranium CSF in the 3D-real IR image. The signal intensity (SI)-increase of the ventricular CSF and the extra-ventricular CSF at 4 h post-administration of GBCA compared to pre-administration was measured. The relationship between the age of the patient and the SI-increase was evaluated. Results: A correlation between age and the SI-increase was observed in the whole-cranium CSF. The correlation coefficient between age and the SI-increase in the ventricular CSF was higher than that in the extra-ventricular CSF. Conclusion: An age-related leakage of the intravenously administered GBCAs was found in the whole-brain CSF. The age-related change in the distribution of the GBCA leakage was more prominent in the ventricular CSF than in the extra-ventricular CSF.

DOI： 10.1007/s11604-020-01079-0

Early glottic cancer treatment with concurrent chemoradiotherapy with once-daily orally administered S-1 Reviewed

Yuuki Takase, Yoshiyuki Itoh, Kazuhiro Ohtakara, Mariko Kawamura, Junji Ito, Yumi Oie, Tamami Ono, Yutaro Sasaki, Ayumi Nishida, Shinji Naganawa

Nagoya Journal of Medical Science Vol. 83 ( 2 ) page： 251 - 258 2021.5

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：Nagoya University

Glottic carcinoma is the most common laryngeal cancer. The outcomes for T1 bulky Glottic carcinoma and T2N0 Glottic carcinoma after radiation therapy alone are unsatisfactory. This study was conducted to evaluate the efficacy and safety of unique concurrent chemoradiotherapy regimen using S-1 for early glottic cancer. Concurrent chemoradiotherapy consisted of 60 Gy in 30 fractions with once-daily, orally administered S-1 exclusively within three to six hours prior to each irradiation. Twenty-one consecutive patients treated with this regimen were retrospectively reviewed. Initial complete remission was achieved in all patients without any subsequent local and/or regional recurrences to the last follow-up. The 4-year local control, overall survival, and disease-free survival rates were all 100%. No significant toxicities were observed, except for three cases with Grade 3 acute dermatitis. This regimen is highly effective and well-tolerated, and these results encourage further research to long-term efficacy and functional preservation.

DOI： 10.18999/nagjms.83.2.251

Diffusion analysis of fluid dynamics with incremental strength of motion proving gradient (DANDYISM) to evaluate cerebrospinal fluid dynamics Reviewed

Toshiaki Taoka, Hisashi Kawai, Toshiki Nakane, Takashi Abe, Rei Nakamichi, Rintaro Ito, Yuki Sato, Mayuko Sakai, Shinji Naganawa

Japanese Journal of Radiology Vol. 39 ( 4 ) page： 315 - 323 2021.4

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

<title>Abstract</title><sec>
<title>Purpose</title>
To visualize and analyze the dynamics of cerebrospinal fluid (CSF) motion in the cranium, we evaluated the distribution of motion-related signal dephasing by CSF on Diffusion ANalysis of fluid DYnamics with Incremental Strength of Motion proving gradient (DANDYISM) method, a composite imaging method using various low <italic>b</italic> values.

</sec><sec>
<title>Materials and methods</title>
This study examined ten subjects aged 25–58. We acquired DWIs on a 3T clinical scanner with <italic>b</italic> values 0, 50, 100, 200, 300, 500, 700, and 1000 s/mm2 in total imaging time of 4 min. We constructed DANDYISM images and evaluated the CSF area distribution with decreased motion-dephasing signal using a scoring method.

</sec><sec>
<title>Results</title>
The DANDYISM images showed statistically significant higher CSF scores in the ventral posterior fossa, suprasellar cistern, and Sylvian vallecula compared to the lateral ventricle and frontal and parietal CSF spaces, indicating greater CSF movement in the former areas.

</sec><sec>
<title>Conclusion</title>
The results indicated prominent CSF motions in the ventral portion of the posterior fossa, suprasellar cistern, and Sylvian fissure but smaller motions in the lateral ventricles and parietal subarachnoid space. This method may provide information of CSF dynamics in the clinical settings within short imaging time.

</sec>

DOI： 10.1007/s11604-020-01075-4

Variation in thyroid volumes due to differences in the measured length or area of the cross-sectional plane: A validation study of the ellipsoid approximation method using CT images Reviewed

Other Link： http://link.springer.com/article/10.1007/s11604-020-01075-4/fulltext.html

Naotoshi Fujita, Katsuhiko Kato, Shinji Abe, Shinji Naganawa

Journal of Applied Clinical Medical Physics Vol. 22 ( 4 ) page： 15 - 25 2021.4

Authorship：Last author Language：English Publishing type：Research paper (scientific journal) Publisher：John Wiley and Sons Ltd

Purpose: This study examined the variation in the thyroid volume determined by the ellipsoid approximation method due to differences in the measured length or area of the cross-sectional plane of CT images. Methods: Forty-five patients with Graves' disease were included in this retrospective study. We designated the three-dimensional thyroid volumes extracted manually (VCT) as the reference data and calculated five approximate volumes for comparison: (a) the mean volume of 8100 different thyroid volumes depending on the diameter of the cross-sectional plane at the midpoint of the major axis, (Vellipsoid,mean)
(b) the volume using the maximum diameter and its orthogonal diameter, (Vellipsoid,maxlength)
(c) the maximum (Vellipsoid,maxvolume)
(d) minimum (Vellipsoid,minvolume) of the 8100 thyroid volumes
and (e) the volume determined with an equivalent circle diameter, (Vellipsoid,Heywood). Results: Thyroid volumes obtained via the ellipsoid approximation method varied depending on the diameter of the cross-sectional plane and included a mean error of approximately 20%, while the concordance correlation coefficient (CCC) differed for each approximate volume. Among these volumes, Vellipsoid,mean and Vellipsoid,Heywood were in good agreement with VCT, according to single regression analyses and the resultant CCC values, with mean errors of 0.1% and 10.4%, respectively. Conclusion: While Vellipsoid,Heywood approximated thyroid volumes with vastly reduced errors, we recommend utilizing three-dimensional thyroid volumetry if measurement accuracy is required.

DOI： 10.1002/acm2.13125

【Precision Medicine時代のCardiac Imaging 2021 後編】MRI:循環器領域における臨床の最前線と技術の到達点 MRIの技術革新が広げる循環器画像診断の可能性大血管の4D flow MRI Reviewed

櫻井康雄, 竹原康雄, 水野崇, 阿部真治, 長縄慎二

INNERVISION Vol. 36 ( 5 ) page： 7 - 9 2021.4

Authorship：Last author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：(株)インナービジョン

MRIは、周辺技術の進歩により高画質、高速化が進められ、画像診断において重要な位置を占めている。MRによる生体内情報として、各組織のプロトンの密度、T1緩和、T2緩和、磁化率、拡散、血流、体液の流れ、灌流情報などの画像化、代謝情報が得られるが、その中で、血流や体液の流速を計測する試みは、位相コントラスト法を用いて古くから行われてきた。本稿では、血管領域に関する機能画像として、研究段階ではあるが、三次元の空間に時間軸情報を加えた三次元シネ位相コントラスト(phase contrast:PC)法である「4D flow MRI」について、主として大血管における現状を紹介する。(著者抄録)

Time-resolved 3D cine phase-contrast magnetic resonance imaging (4D-flow MRI) can quantitatively assess portosystemic shunt severity and confirm normalization of portal flow after embolization of large portosystemic shunts. International journal

Ryota Hyodo, Yasuo Takehara, Takashi Mizuno, Kazushige Ichikawa, Yoji Ishizu, Masataka Sugiyama, Shinji Naganawa

Hepatology research : the official journal of the Japan Society of Hepatology Vol. 51 ( 3 ) page： 343 - 349 2021.3

Language：English Publishing type：Research paper (scientific journal)

Diagnosis and severity assessments of portosystemic shunts (PSSs) are important because the pathology sometimes results in severe hepatic encephalopathy, which can be treated almost completely by shunt embolization. At present, morphological assessment of PSS is performed mainly by computed tomography, and ultrasound is used for blood flow assessment. In two cases of PSS-related hepatic encephalopathy, we used time-resolved 3D cine phase-contrast (4D-flow) magnetic resonance imaging (MRI) to assess blood flow before and after shunt embolization. Before the intervention, blood flow in the main trunk of the superior mesenteric vein was mostly hepatofugal. However, post-interventional 4D-flow MRI revealed hepatopetal superior mesenteric vein flow with significantly increased portal vein blood flow. 4D-flow MRI is an ideal adjunct to Doppler ultrasonography, allowing for objective and visual assessment of morphology and blood flow of the portal venous system, including PSSs, and is useful in determining the indications for, and outcome of, PSS embolization.

DOI： 10.1111/hepr.13616

MRによる頭蓋内間質液・脳脊髄液動態の解明 Invited Reviewed

長縄慎二、田岡俊昭、川井　恒

脳とこころの研究センター　脳疾患克服に向けた次世代創薬開発のためのコホート・コンソーシアム型研究拠点形成 Vol. - ( - ) page： 23 - 23 2021.3

TGSE-Radial Sampling型DWIにおける自作ファントムを用いたADC値と磁化率歪みの評価 Reviewed

加藤裕, 熊谷始紀, 奥平訓康, 丸山克也, 田岡俊昭, 長縄慎二

日本放射線技術学会総会学術大会予稿集 Vol. 77回 page： 200 - 200 2021.3

Imaging of endolymphatic hydrops on a vertigo attack of Meniere's disease. Reviewed

Takafumi Nakada, Masaaki Teranishi, Saiko Sugiura, Yasue Uchida, Shinji Naganawa, Michihiko Sone

Nagoya journal of medical science Vol. 83 ( 1 ) page： 209 - 216 2021.2

Language：English Publishing type：Research paper (scientific journal)

Meniere's disease (MD) characteristically presents with endolymphatic hydrops (EH), which can be visualized with gadolinium-enhanced inner ear magnetic resonance imaging (MRI). Inner ear membrane rupture has been suspected to cause MD attacks, but this remains controversial. We report a case of MD coincidentally evaluated the EH using 3-Tesla MRI during a vertigo attack. A 78-year-old man with bilateral definite MD visited the hospital outpatient department due to a vertigo attack. To evaluate of endolymphatic hydrops on the attack, inner ear MRI was obtained 4 hours after intravenous injection of gadolinium agent. Vestibular EH in each ear occupied almost all vestibular endolymphatic space in contact with the oval window and herniated into the horizontal semi-circular canal. The endolymphatic space was enlarged, without collapse or mixture of contrast agent. No difference was found between ears. EH on a vertigo attack was associated with significant swelling, without obvious evidence of membranous ruptures on magnetic resonance images.

DOI： 10.18999/nagjms.83.1.209

コロナウイルス肺炎のAi診断 Invited Reviewed

伊藤倫太郎、岩野信吾、長縄慎二

臨床免疫・アレルギー科 Vol. 75 ( 2 ) page： 189 - 193 2021.2

Shingo Iwano, Shinichiro Kamiya, Rintaro Ito, Shota Nakamura, Shinji Naganawa

Cancer imaging : the official publication of the International Cancer Imaging Society Vol. 21 ( 1 ) page： 7 - 7 2021.1

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: To investigate the correlation between iodine-related attenuation in contrast-enhanced dual-energy computed tomography (DE-CT) and the postoperative prognosis of surgically resected solid-type small-sized lung cancers. METHODS: We retrospectively reviewed the DE-CT findings and postoperative course of solid-type lung cancers ≤3 cm in diameter. After injection of iodinated contrast media, arterial phases were scanned using 140-kVp and 80-kVp tube voltages. Three-dimensional iodine-related attenuation (3D-IRA) of primary tumors at the arterial phase was computed using the "lung nodule" application software. The corrected 3D-IRA normalized to the patient's body weight and contrast medium concentration was then calculated. RESULTS: A total of 120 resected solid-type lung cancers ≤3 cm in diameter were selected for analysis (82 males and 38 females; mean age, 67 years). During the observation period (median, 47 months), 32 patients showed postoperative recurrence. Recurrent tumors had significantly lower 3D-IRA and corrected 3D-IRA at early phase compared to non-recurrent tumors (p = 0.046 and p = 0.027, respectively). The area under the receiver operating characteristic curve for postoperative recurrence was 0.624 for the corrected 3D-IRA at early phase (p = 0.025), and the cutoff value was 5.88. Kaplan-Meier curves for disease-free survival indicated that patients showing tumors with 3D-IRA > 5.88 had a significantly better prognosis than those with tumors showing 3D-IRA < 5.88 (p = 0.017). CONCLUSIONS: The 3D-IRA of small-sized solid-type lung cancers on contrast-enhanced DE-CT was significantly associated with postoperative prognosis, and low 3D-IRA tumors showed a higher TNM stage and a significantly poorer prognosis.

DOI： 10.1186/s40644-020-00368-1

Lesion-specific prognosis by magnetic resonance imaging in sudden sensorineural hearing loss. Reviewed International journal

Cheng-Jui Yang, Tadao Yoshida, Satofumi Sugimoto, Masaaki Teranishi, Masumi Kobayashi, Naoki Nishio, Shinji Naganawa, Michihiko Sone

Acta oto-laryngologica Vol. 141 ( 1 ) page： 5 - 9 2021.1

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: High signals in the inner ear of idiopathic sudden sensorineural hearing loss (ISSNHL) on magnetic resonance imaging (MRI) have been reported, but no quantitative evaluation has yet been done. OBJECTIVES: To evaluate hearing outcomes and cochlear signal intensities on 3-T heavily T2-weighted three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (hT2W-3D-FLAIR) in patients with ISSNHL. MATERIALS AND METHODS: Twenty-nine patients with ISSNHL were included. Patients underwent hT2W-3D-FLAIR with intravenous gadolinium injection and pure tone audiometry (PTA) at initial visits and 3 months later. Signal intensity ratios (SIRs) were measured in the basal or apical-middle turns of the affected cochlea. A statistical analysis of relationships between SIRs and the average hearing levels (HLs) at low (125, 250, and 500 Hz) and high (2, 4, and 8 kHz) tone frequencies was performed. RESULTS: Hearing improvements at high-tone frequencies in ears with HLs ≥60 dB were significantly worse in those with high SIRs at the basal turns on pre-contrast images. Similarly, hearing improvements at low-tone frequencies in ears with HLs ≥60 dB were significantly worse in those with high SIRs at the apical-middle turns on post-contrast images. CONCLUSIONS AND SIGNIFICANCE: High SIRs on hT2W-3D-FLAIR indicate cochlear disturbances with severe ISSNHL and could provide lesion-specific prognostic information.

DOI： 10.1080/00016489.2020.1827159

Imaging for central nervous system (CNS) interstitial fluidopathy: disorders with impaired interstitial fluid dynamics. Reviewed

Toshiaki Taoka, Shinji Naganawa

Japanese journal of radiology Vol. 39 ( 1 ) page： 1 - 14 2021.1

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

After the introduction of the glymphatic system hypothesis, an increasing number of studies on cerebrospinal fluid and interstitial fluid dynamics within the brain have been investigated and reported. A series of diseases are known which develop due to abnormality of the glymphatic system including Alzheimer's disease, traumatic brain injury, stroke, or other disorders. These diseases or disorders share the characteristics of the glymphatic system dysfunction or other mechanisms related to the interstitial fluid dynamics. In this review article, we propose "Central Nervous System (CNS) Interstitial Fluidopathy" as a new concept encompassing diseases whose pathologies are majorly associated with abnormal interstitial fluid dynamics. Categorizing these diseases or disorders as "CNS interstitial fluidopathies," will promote the understanding of their mechanisms and the development of potential imaging methods for the evaluation of the disease as well as clinical methods for disease treatment or prevention. In other words, having a viewpoint of the dynamics of interstitial fluid appears relevant for understanding CNS diseases or disorders, and it would be possible to develop novel common treatment methods or medications for "CNS interstitial fluidopathies."

DOI： 10.1007/s11604-020-01017-0

Distribution of gadolinium-based contrast agent after leaking into the cerebrospinal fluid: Comparison between the cerebral cisterns and the lateral ventricles Reviewed

Toshio Ohashi, Shinji Naganawa, Saeko Iwata, Kayao Kuno

Magnetic Resonance in Medical Sciences Vol. 20 ( 2 ) page： 175 - 181 2021

Language：English Publishing type：Research paper (scientific journal) Publisher：Japanese Society for Magnetic Resonance in Medicine

Purpose: Leakage of a small amount of intravenously administered gadolinium-based contrast agents (GBCAs) into the cerebrospinal fluid (CSF) space has been reported, even in healthy subjects without blood-brain barrier disruption. Several candidates including the choroid plexus and cortical veins have been proposed as the source of the leakage. The purpose of this study was to evaluate the distribution of intravenously administered GBCA leakage into the CSF by comparing the contrast enhancement of the cerebral cisterns to the lateral ventricles (LVs). Methods: In 26 patients with a suspicion of endolymphatic hydrops (21-80 years old), a three-dimensional real inversion recovery (3D-real IR) image was obtained at pre-, and at 5 min, and 4 h post-intravenous administration of a single dose of GBCA (IV-SD-GBCA). In the 3D-real IR image, the signal intensities (SIs) in the anterior horn of the LV (LVante), the trigone of the LV (LVtri), the Sylvian fissure (SyF), the ambient cistern (Amb), the prepontine cistern (PPC), the cerebellopontine angle cistern (CPA), and the vitreous (Vit) were measured. The differences in the SI at pre-, and at 5 min and 4 h post-IV-SD-GBCA were evaluated for each region. The change in the SI pre- to post-IV-SD-GBCA (SIchange) were calculated for each region. The differences in the SIchange in each region were evaluated at 5 min and 4 h post-IV-SD-GBCA. A Steel-Dwass’s test was applied to correct for multiple comparisons. Results: The SIs of all regions at 4 h post-IV-SD-GBCA were significantly higher compared with pre-IV-SD-GBCA (P &lt
0.05). The SIchange in the SyF, Amb, PPC, and the CPA were significantly higher compared with those of the LVante, LVtri, and the Vit at 4 h post-IV-SD-GBCA (P &lt
0.05). Conclusion: The contrast enhancement in the cerebral cisterns was greater than that in the LVs.

DOI： 10.2463/mrms.mp.2020-0016

Three Dimensional Ultra-short Echo Time MRI Can Depict Cholesterol Components of Gallstones Bright. Reviewed

Mamoru Takahashi, Yasuo Takehara, Kenji Fujisaki, Tomoyuki Okuaki, Yukiko Fukuma, Norihiro Tooyama, Katsutoshi Ichijo, Tomoyasu Amano, Satoshi Goshima, Shinji Naganawa

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 20 ( 4 ) page： 359 - 370 2021

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Non-calcified cholesterol stones that are small in size are hard to be depicted on CT or magnetic resonance cholangiopancreatography. This institutional review board (IRB)-approved retrospective in vitro study aims to characterize contrast behaviors of 3 main components of the gallstones, i.e., cholesterol component (CC), bilirubin calcium component (BC) and CaCO3 (CO) on 3D radial scan with ultrashort TE (UTE) MRI, and to test the capability of depicting CC of gallstones as bright signals as compared to background saline. METHODS: Fourteen representative gallstones from 14 patients, including 15 CC, 6 BC and 4 CO, were enrolled. The gallstones underwent MRI including fat-saturated T1-weighted image (fs-T1WI) and UTE MRI with dual echoes. The contrast-to-noise ratio (CNR) and the chemical analysis for the 25 portions of the stones were compared. RESULTS: BC was bright on fs-T1WI, which did not change dramatically on UTE MRI and the signal did not remain on UTE subtraction image between dual echoes. Whereas the CC was negative or faintly positive signal on fs-T1WI, bright signal on UTE MRI and the contrast remained even higher on the UTE subtraction, which reflected their short T2 values. Median CNRs and standard errors of the segments on each imaging were as follows: on fs-T1WI, -10.2 ± 4.2 for CC, 149.7 ± 27.6 for BC and 37.9 ± 14.3 for CO; on UTE MRI first echo, 16.7 ± 3.3 for CC, 74.9 ± 21.3 for BC and 17.7 ± 8.4 for CO; on UTE subtraction image, 30.2 ±2.0 for CC, -11.2 ± 5.4 for BC and 17.8 ± 10.7 for CO. Linear correlations between CNRs and cholesterol concentrations were observed on fs-T1WI with r = -0.885, (P < 0.0001), UTE MRI first echo r = -0.524 (P = 0.0072) and UTE subtraction with r = 0.598 (P = 0.0016). CONCLUSION: UTE MRI and UTE subtraction can depict CC bright.

DOI： 10.2463/mrms.mp.2020-0009

Relationship between Time-dependent Signal Changes in Parasagittal Perivenous Cysts and Leakage of Gadolinium-based Contrast Agents into the Subarachnoid Space. Reviewed

Shinji Naganawa, Rintaro Ito, Rei Nakamichi, Mariko Kawamura, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 20 ( 4 ) page： 378 - 384 2021

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: To investigate the association between signal changes over time in perivenous cystic structures near the superior sagittal sinus and leakage of a gadolinium-based contrast agent (GBCA) into the subarachnoid space in patients with suspected endolymphatic hydrops. METHODS: Fifty-one cystic structures in 27 cases were evaluated. The signal intensity of the cystic structures was measured on 3D real inversion recovery (3D-real IR) images obtained at pre-, and at 10 min, 4 hrs and 24 hrs post-intravenous administration (IV) of GBCA. Signal enhancement of the cystic structures from the pre-contrast images at each time point was compared in subjects with leakage (positive) versus those without leakage (negative) using an ANOVA. Fisher's exact probability test was used to compare the maximum contrast-enhanced time point between positive and negative groups. We used 5% as a threshold to determine statistical significance. RESULTS: In leakage positive subjects, mean signal enhancement of the cysts was significantly greater at 4 and 24 hrs compared to 10 min. However, although there was a trend of an increase from 4 to 24 hrs, the difference was not significant. In the leakage negative group, mean signal enhancement of the cysts was significantly higher at 4 hrs compared to 10 min and 24 hrs. There was no significant difference between 10 min and 24 hrs. In the positive group, the maximum signal increase was found in 10/38 and 28/38 cysts at 4 and 24 hrs after IV-GBCA, respectively. In the leakage negative group, the maximum signal increase was found in 10/13 and 3/13 cysts at 4 and 24 hrs, respectively (P = 0.0019). CONCLUSION: There was an association between signal changes over time after IV-GBCA in perivenous cystic structures and leakage of GBCA. Further research to clarify the impact of cystic structures on the function of the waste clearance system of the brain is warranted.

DOI： 10.2463/mrms.mp.2020-0138

Relationship between Parasagittal Perivenous Cysts and Leakage of Gadolinium-based Contrast Agents into the Subarachnoid Space around the Cortical Veins after Intravenous Administration. Reviewed

Shinji Naganawa, Rintaro Ito, Rei Nakamichi, Mariko Kawamura, Hisashi Kawai, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 20 ( 3 ) page： 245 - 252 2021

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The purpose of this retrospective study was to investigate the relationship between the number and size of cystic structures around the cortical veins near the superior sagittal sinus and the leakage of gadolinium-based contrast agent (GBCA) around the cortical veins. METHODS: Of 190 patients (91 male and 99 female), that were scanned at 4 h after an intravenous injection of GBCA as a diagnostic examination for endolymphatic hydrops, 6 patients with GBCA leakage were younger than the previously proposed threshold age of 37.3 years for leakage. Six age-matched patients without leakage were also included for reference. In addition, we included 8 cases without leakage that were older than the hypothesized threshold of 37.3 years, as well as 8 age-matched patients with GBCA leakage into the cerebrospinal fluid space. The number of cysts was counted and the sizes were measured in these 28 patients (age: 32-60 years old, 13 men and 15 women). RESULTS: The mean number of cysts surrounding the cortical veins in the parasagittal region was 4.29 ± 1.77 vs. 1.79 ± 1.05 (P = 0.0001) in the subjects with and without GBCA leakage, respectively. The mean size of the largest cysts was at 8.89 ± 3.49 mm vs. 5.69 ± 2.29 (P = 0.009) in the subjects with and without GBCA leakage, respectively. CONCLUSION: The number and size of the perivenous cystic structures near the superior sagittal sinus is greater in subjects with GBCA leakage into the subarachnoid space compared with those without leakage. Future research regarding the histological and functional details of these parasagittal cystic structures is needed.

DOI： 10.2463/mrms.mp.2020-0062

Portal Vein Stenosis Following Liver Transplantation Hemodynamically Assessed with 4D-flow MRI before and after Portal Vein Stenting. Reviewed

Ryota Hyodo, Yasuo Takehara, Takashi Mizuno, Kazushige Ichikawa, Yasuhiro Ogura, Shinji Naganawa

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 20 ( 3 ) page： 231 - 235 2021

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

We present a case of a patient who underwent portal vein (PV) stenting for PV stenosis after a living-donor liver transplantation. A pretreatment 3D cine phase-contrast (4D-flow) MRI showed decreased, though hepatopetal, blood flow in the PV. After stenting, 4D-flow MRI confirmed an improvement in PV flow, with a more homogeneous flow distribution to each hepatic segment. 4D-flow MRI are valuable for understanding the hemodynamics of this area, planning for treatments, and evaluating the outcome of the interventions.

DOI： 10.2463/mrms.ici.2020-0057

MR Imaging of Endolymphatic Hydrops: Utility of iHYDROPS-Mi2 Combined with Deep Learning Reconstruction Denoising. Reviewed

Shinji Naganawa, Rei Nakamichi, Kazushige Ichikawa, Mariko Kawamura, Hisashi Kawai, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 20 ( 3 ) page： 272 - 279 2021

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: MRI of endolymphatic hydrops (EH) 4 h after intravenous administration of a single dose of gadolinium-based contrast agent is used for clinical examination in some institutions; however, further improvement in image quality would be valuable for wider clinical utility. Denoising using deep learning reconstruction (Advanced Intelligent Clear-IQ Engine [AiCE]) has been reported for CT and MR. The purpose of this study was to compare the contrast-to-noise ratio of endolymph to perilymph (CNREP) between the improved hybrid of reversed image of the positive endolymph signal and the native image of the perilymph signal multiplied with the heavily T2-weighted MR cisternography (iHYDROPS-Mi2) images, which used AiCE for the three source images (i.e. positive endolymph image [PEI], positive perilymph image [PPI], MR cisternography [MRC]) to those that did not use AiCE. We also examined if there was a difference between iHYDROPS-Mi2 images with and without AiCE for degree of visual grading of EH and in endolymphatic area [EL] ratios. METHODS: Nine patients with suspicion of EH were imaged on a 3T MR scanner. iHYDROPS images were generated by subtraction of PEI images from PPI images. iHYDROPS-Mi2 images were then generated by multiplying MRC with iHYDROPS images. The CNREP and EL ratio were measured on the iHYDROPS-Mi2 images. Degree of radiologist visual grading for EH was evaluated. RESULTS: Mean CNREP ± standard deviation was 1681.8 ± 845.2 without AiCE and 7738.6 ± 5149.2 with AiCE (P = 0.00002). There was no significant difference in EL ratio for images with and without AiCE. Radiologist grading for EH agreed completely between the 2 image types in both the cochlea and vestibule. CONCLUSION: The CNREP of iHYDROPS-Mi2 images with AiCE had more than a fourfold increase compared with that without AiCE. Use of AiCE did not adversely affect radiologist grading of EH.

DOI： 10.2463/mrms.mp.2020-0082

Intracranial Distribution of Intravenously Administered Gadolinium-based Contrast Agent over a Period of 24 Hours: Evaluation with 3D-real IR Imaging and MR Fingerprinting. Reviewed

Shinji Naganawa, Rintaro Ito, Yutaka Kato, Hisashi Kawai, Toshiaki Taoka, Tadao Yoshida, Katsuya Maruyama, Katsutoshi Murata, Gregor Körzdörfer, Josef Pfeuffer, Mathias Nittka, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 20 ( 1 ) page： 91 - 98 2021

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: To evaluate the feasibility for the detection of slight contrast effects after intravenous administration of single dose gadolinium-based contrast agent (IV-SD-GBCA), the time course of the GBCA distribution up to 24 h was examined in various fluid spaces and brain parenchyma using 3D-real IR imaging and MR fingerprinting (MRF). METHODS: Twenty-four patients with a suspicion of endolymphatic hydrops were scanned at pre-administration and at 10 min, 4 and 24 h post-IV-SD-GBCA. 3D-real IR images and MRF at the level of the internal auditory canal were obtained. The signal intensity on the 3D-real IR image of the cerebrospinal fluid (CSF) in the cerebellopontine angle cistern (CPA), Sylvian fissure (Syl), lateral ventricle (LV), and cochlear perilymph (CPL) was measured. The T1 and T2 values of cerebellar gray (GM) and white matter (WM) were measured using MRF. Each averaged value at the various time points was compared using an analysis of variance. RESULTS: The signal intensity on the 3D-real IR image in each CSF region peaked at 4 h, and was decreased significantly by 24 h (P< 0.05). All patients had a maximum signal intensity at 4 h in the CPA, and Syl. The mean CPL signal intensity peaked at 4 h and decreased significantly by 24 h (P < 0.05). All patients but two had a maximum signal intensity at 4 h. Regarding the T1 value in the cerebellar WM and GM, the T1 value at 10 min post-IV-GBCA was significantly decreased compared to the pre-contrast scan, but no significant difference was observed at the other time points. There was no significant change in T2 in the gray or white matter at any of the time points. CONCLUSION: Time course of GBCA after IV-SD-GBCA could be evaluated by 3D-real IR imaging in CSF spaces and in the brain by MRF.

DOI： 10.2463/mrms.mp.2020-0030

特集「世界の医療・Radiology：海外事情を覗き見よう」ドイツ編 Reviewed

長縄慎二

JCRニュース (日本放射線科専門医会・医会誌) Vol. 238 ( - ) page： 11 - 13 2021

A case of stent-graft implantation for postpancreaticoduodenectomy hemorrhage in a patient with a reconstructed gastric tube

Tomohiro Komada, Yasushi Tachi, Ken Nagasaka, Suguru Yamada, Masaya Matsushima, Yutaro Sakaki, Shinji Naganawa

Radiology Case Reports Vol. 15 ( 12 ) page： 2710 - 2713 2020.12

Evaluation of magnetic resonance angiography as a possible alternative to rotational angiography or computed tomography angiography for assessing cerebrovascular computational fluid dynamics. Reviewed International journal

Yuya Yoneyama, Haruo Isoda, Kenta Ishiguro, Masaki Terada, Masaki Kamiya, Kenichi Otsubo, Roshani Perera, Takashi Mizuno, Atsushi Fukuyama, Kazuya Takiguchi, Tomoya Watanabe, Takafumi Kosugi, Yoshiaki Komori, Shinji Naganawa

Physical and engineering sciences in medicine Vol. 43 ( 4 ) page： 1327 - 1337 2020.12

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

The aim of this study was to conduct a flow experiment using a cerebrovascular phantom and investigate whether magnetic resonance angiography (MRA) could replace three-dimensional rotational angiography (RA) and computed tomography angiography (CTA) to construct vascular models for computational fluid dynamics (CFD). We performed MRA and 3D cine phase-contrast (PC) MR imaging with a silicone cerebrovascular phantom of an internal carotid artery-posterior communicating artery aneurysm with blood-mimicking fluid, and controlled flow with a flowmeter. We also obtained RA and CTA data for the phantom. Four analysts constructed vascular models based on the three different modalities. These 12 constructed models used flow information based on 3D cine PC MR imaging for CFD. We compared RA-, CTA-, MRA-based CFD results using the micro-CT-based CFD result as the criterion standard to investigate whether MRA-based CFD was not inferior to RA- or CTA-based CFD. We also analyzed the inter-analyst variability. Wall shear stress (WSS) distributions and streamlines of RA- or MRA-based CFD and those of micro-CT-based CFD were similar, but the vascular models and WSS values were different. Accuracy in measurements of blood vessel diameter, cross-sectional maximum velocity, and spatially averaged WSS was the highest for RA-based CFD, followed by MRA-based and CTA-based CFD using micro-CT-based CFD result as the reference. Except maximum velocity from CTA, all other parameters had good inter-analyst agreement using different modalities. The results demonstrated that non-invasive MRA can be used for cerebrovascular CFD models with good inter-analyst agreements.

DOI： 10.1007/s13246-020-00936-6

【基調論文】CTおよびMRIなどの画像診断装置の今後の展望 Reviewed

長縄慎二

月間新医療データブック・シリーズ　医療機器システム白書 Vol. - ( - ) page： 14 - 18 2020.12

【特集】　マネジメントに苦慮する疾患： Is it benign, malignant or insignificant? 1. 甲状腺病変の診断とマネジメント Invited Reviewed

石垣聡子、佐竹弘子、松本篤子、林　葉子、清水友理、長縄慎二

日獨医報 Vol. 65 ( 1 ) page： 5 - 11 2020.12

Identifying the brain's connector hubs at the voxel level using functional connectivity overlap ratio. Reviewed International journal

Epifanio Bagarinao, Hirohisa Watanabe, Satoshi Maesawa, Daisuke Mori, Kazuhiro Hara, Kazuya Kawabata, Reiko Ohdake, Michihito Masuda, Aya Ogura, Toshiyasu Kato, Shuji Koyama, Masahisa Katsuno, Toshihiko Wakabayashi, Masafumi Kuzuya, Minoru Hoshiyama, Haruo Isoda, Shinji Naganawa, Norio Ozaki, Gen Sobue

NeuroImage Vol. 222 page： 117241 - 117241 2020.11

Language：English Publishing type：Research paper (scientific journal)

Neuroimaging studies have shown that the brain is functionally organized into several large-scale brain networks. Within these networks are regions that are widely connected to several other regions within and/or outside the network. Regions that connect to several other networks, known as connector hubs, are believed to be crucial for information transfer and between-network communication within the brain. To identify regions with high between-network connectivity at the voxel level, we introduced a novel metric called functional connectivity overlap ratio (FCOR), which quantifies the spatial extent of a region's connection to a given network. Using resting state functional magnetic resonance imaging data, FCOR maps were generated for several well-known large-scale resting state networks (RSNs) and used to examine the relevant associations among different RSNs, identify connector hub regions in the cerebral cortex, and elucidate the hierarchical functional organization of the brain. Constructed FCOR maps revealed a strong association among the core neurocognitive networks (default mode, salience, and executive control) as well as among primary processing networks (sensorimotor, auditory, and visual). Prominent connector hubs were identified in the bilateral middle frontal gyrus, posterior cingulate, lateral parietal, middle temporal, dorsal anterior cingulate, and anterior insula, among others, regions mostly associated with the core neurocognitive networks. Finally, clustering the whole brain using FCOR features yielded a topological organization that arranges brain regions into a hierarchy of information processing systems with the primary processing systems at one end and the heteromodal systems comprising connector hubs at the other end.

DOI： 10.1016/j.neuroimage.2020.117241

Neurofluid Dynamics and the Glymphatic System: A Neuroimaging Perspective. Reviewed International journal

Toshiaki Taoka, Shinji Naganawa

Korean journal of radiology Vol. 21 ( 11 ) page： 1199 - 1209 2020.11

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

The glymphatic system hypothesis is a concept describing the clearance of waste products from the brain. The term "glymphatic system" combines the glial and lymphatic systems and is typically described as follows. The perivascular space functions as a conduit that drains cerebrospinal fluid (CSF) into the brain parenchyma. CSF guided to the perivascular space around the arteries enters the interstitium of brain tissue via aquaporin-4 water channels to clear waste proteins into the perivascular space around the veins before being drained from the brain. In this review, we introduce the glymphatic system hypothesis and its association with fluid dynamics, sleep, and disease. We also discuss imaging methods to evaluate the glymphatic system.

DOI： 10.3348/kjr.2020.0042

Aging Impacts the Overall Connectivity Strength of Regions Critical for Information Transfer Among Brain Networks Invited International journal Open Access

Epifanio Bagarinao, Hirohisa Watanabe, Satoshi Maesawa, Daisuke Mori, Kazuhiro Hara, Kazuya Kawabata, Noritaka Yoneyama, Reiko Ohdake, Kazunori Imai, Michihito Masuda, Takamasa Yokoi, Aya Ogura, Toshiaki Taoka, Shuji Koyama, Hiroki C. Tanabe, Masahisa Katsuno, Toshihiko Wakabayashi, Masafumi Kuzuya, Minoru Hoshiyama, Haruo Isoda, Shinji Naganawa, Norio Ozaki, Gen Sobue

Frontiers in Aging Neuroscience Vol. 12 page： 592469 - 592469 2020.10

Language：English Publishing type：Research paper (scientific journal) Publisher：Frontiers Media SA

Recent studies have demonstrated that connector hubs, regions considered critical for the flow of information across neural systems, are mostly involved in neurodegenerative dementia. Considering that aging can significantly affect the brain's intrinsic connectivity, identifying aging's impact on these regions' overall connection strength is important to differentiate changes associated with healthy aging from neurodegenerative disorders. Using resting state functional magnetic resonance imaging data from a carefully selected cohort of 175 healthy volunteers aging from 21 to 86 years old, we computed an intrinsic connectivity contrast (ICC) metric, which quantifies a region's overall connectivity strength, for whole brain, short-range, and long-range connections and examined age-related changes of this metric over the adult lifespan. We have identified a limited number of hub regions with ICC values that showed significant negative relationship with age. These include the medial precentral/midcingulate gyri and insula with both their short-range and long-range (and thus whole-brain) ICC values negatively associated with age, and the angular, middle frontal, and posterior cingulate gyri with their long-range ICC values mainly involved. Seed-based connectivity analyses further confirmed that these regions are connector hubs with connectivity profile that strongly overlapped with multiple large-scale brain networks. General cognitive performance was not associated with these hubs' ICC values. These findings suggest that even healthy aging could negatively impact the efficiency of regions critical for facilitating information transfer among different functional brain networks. The extent of the regions involved, however, was limited.

DOI： 10.3389/fnagi.2020.592469

Significance of high signal intensity in the endolymphatic duct on magnetic resonance imaging in ears with otological disorders. Reviewed International journal

Kyoko Morimoto, Tadao Yoshida, Masumi Kobayashi, Satofumi Sugimoto, Naoki Nishio, Masaaki Teranishi, Shinji Naganawa, Michihiko Sone

Acta oto-laryngologica Vol. 140 ( 10 ) page： 818 - 822 2020.10

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: High signal intensity in the endolymphatic duct (ED) is occasionally observed on magnetic resonance imaging (MRI) in ears that have otological disorders. OBJECTIVE: The signal intensity (SI) in the ED on post-contrast MRI was investigated in subjects with various otological disorders, and the meaning of high SI in the ED was evaluated. MATERIAL AND METHODS: 392 patients with otological disorders and 21 controls without otological symptoms underwent 3 T MRI. The SIs of the ED and the cerebellum were measured, the SI ratio (SIR) was calculated, and ears with SIR ≥4 were identified. RESULTS: A high SIR was identified in the ED of 3.7% of ears affected by definite Meniere's disease (dMD), 100% of ears affected by large vestibular aqueduct syndrome (LVAS), and 7.1% of ears with no otological symptoms. On the whole, a significant relationship was found between the existence of vestibular or cochlear EH and the SIR in the ED. CONCLUSION: The MRI finding of high SI in the ED may indicate the mechanism of inner ear disturbances in ears with otological disorders, especially in those with LVAS, and it may suggest an underlying disorder in some ears in which otological symptoms are not apparent.

DOI： 10.1080/00016489.2020.1781927

Change of White Matter Integrity in Children With Hematopoietic Stem Cell Transplantation. Reviewed International journal

Yoko Sakaguchi, Jun Natsume, Hiroyuki Kidokoro, Masaharu Tanaka, Yu Okai, Yuji Ito, Hiroyuki Yamamoto, Atsuko Ohno, Tomohiko Nakata, Toshiki Nakane, Hisashi Kawai, Toshiaki Taoka, Hideki Muramatsu, Shinji Naganawa, Yoshiyuki Takahashi

Pediatric neurology Vol. 111 page： 78 - 84 2020.10

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Advances in hematopoietic stem cell transplantation have improved the survival rate of malignant diseases and congenital immunodeficiencies. It has become important to assess long-term complications in survivors. To assess neurological abnormalities in children treated by transplantation, diffusion tensor imaging was performed. METHODS: Forty children who underwent head diffusion tensor imaging before and after their first transplantation were enrolled. Patients with brain lesions on conventional MRI were excluded. Fractional anisotropy and mean diffusivity were compared between patients and 28 control subjects using tract-based spatial statistics. The Strengths and Difficulties Questionnaire was administered as a behavioral evaluation after transplantation, and diffusion tensor images of patients with and without behavioral abnormalities were compared. RESULTS: The age of patients and controls was 0 to 19 years and 0 to 16 years, respectively. The date of diffusion tensor imaging was 10 to 57 days before and 40 to 153 days after transplantation. Tract-based spatial statistics showed fractional anisotropy reduction in widespread white matter in patients before and after transplantation. Mean diffusivity was high before transplantation and normalized after transplantation. Analysis comparing before and after hematopoietic stem cell transplantation shows no difference in fractional anisotropy and a higher mean diffusivity before hematopoietic stem cell transplantation. In patients with behavioral abnormalities, low fractional anisotropy and high mean diffusivity remained after transplantation. CONCLUSIONS: Longitudinal diffusion tensor imaging showed white matter abnormalities in children without conventional MRI abnormalities, which were related to behavioral problems after transplantation. Diffusion tensor imaging is useful for behavioral assessment in children undergoing transplantation.

DOI： 10.1016/j.pediatrneurol.2020.06.008

A review on the use of artificial intelligence for medical imaging of the lungs of patients with coronavirus disease 2019. Reviewed International journal

Rintaro Ito, Shingo Iwano, Shinji Naganawa

Diagnostic and interventional radiology (Ankara, Turkey) Vol. 26 ( 5 ) page： 443 - 448 2020.9

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

The results of research on the use of artificial intelligence (AI) for medical imaging of the lungs of patients with coronavirus disease 2019 (COVID-19) has been published in various forms. In this study, we reviewed the AI for diagnostic imaging of COVID-19 pneumonia. PubMed, arXiv, medRxiv, and Google scholar were used to search for AI studies. There were 15 studies of COVID-19 that used AI for medical imaging. Of these, 11 studies used AI for computed tomography (CT) and 4 used AI for chest radiography. Eight studies presented independent test data, 5 used disclosed data, and 4 disclosed the AI source codes. The number of datasets ranged from 106 to 5941, with sensitivities ranging from 0.67-1.00 and specificities ranging from 0.81-1.00 for prediction of COVID-19 pneumonia. Four studies with independent test datasets showed a breakdown of the data ratio and reported prediction of COVID-19 pneumonia with sensitivity, specificity, and area under the curve (AUC). These 4 studies showed very high sensitivity, specificity, and AUC, in the range of 0.9-0.98, 0.91-0.96, and 0.96-0.99, respectively.

DOI： 10.5152/dir.2019.20294

第21回山形めまい研究会　特別講演Ⅰ　MR imaging of endolymphatic hydrops; What is right, what is wrong, and what is new Invited Reviewed

長縄慎二

耳鼻咽喉科山形 (日本耳鼻咽喉科学会山形県地方部会誌) Vol. 24 ( - ) page： 54 - 55 2020.9

Changes in white matter fiber density and morphology across the adult lifespan: A cross-sectional fixel-based analysis. Reviewed International journal

Shao Wei Choy, Epifanio Bagarinao, Hirohisa Watanabe, Eric Tatt Wei Ho, Satoshi Maesawa, Daisuke Mori, Kazuhiro Hara, Kazuya Kawabata, Noritaka Yoneyama, Reiko Ohdake, Kazunori Imai, Michihito Masuda, Takamasa Yokoi, Aya Ogura, Toshiaki Taoka, Shuji Koyama, Hiroki C Tanabe, Masahisa Katsuno, Toshihiko Wakabayashi, Masafumi Kuzuya, Minoru Hoshiyama, Haruo Isoda, Shinji Naganawa, Norio Ozaki, Gen Sobue

Human brain mapping Vol. 41 ( 12 ) page： 3198 - 3211 2020.8

Language：English Publishing type：Research paper (scientific journal)

White matter (WM) fiber bundles change dynamically with age. These changes could be driven by alterations in axonal diameter, axonal density, and myelin content. In this study, we applied a novel fixel-based analysis (FBA) framework to examine these changes throughout the adult lifespan. Using diffusion-weighted images from a cohort of 293 healthy volunteers (89 males/204 females) from ages 21 to 86 years old, we performed FBA to analyze age-related changes in microscopic fiber density (FD) and macroscopic fiber morphology (fiber cross section [FC]). Our results showed significant and widespread age-related alterations in FD and FC across the whole brain. Interestingly, some fiber bundles such as the anterior thalamic radiation, corpus callosum, and superior longitudinal fasciculus only showed significant negative relationship with age in FD values, but not in FC. On the other hand, some segments of the cerebello-thalamo-cortical pathway only showed significant negative relationship with age in FC, but not in FD. Analysis at the tract-level also showed that major fiber tract groups predominantly distributed in the frontal lobe (cingulum, forceps minor) exhibited greater vulnerability to the aging process than the others. Differences in FC and the combined measure of FD and cross section values observed between sexes were mostly driven by differences in brain sizes although male participants tended to exhibit steeper negative linear relationship with age in FD as compared to female participants. Overall, these findings provide further insights into the structural changes the brain's WM undergoes due to the aging process.

DOI： 10.1002/hbm.25008

Efficacy and safety of accelerated fractionated radiotherapy without elective nodal irradiation for T3N0 glottic cancer without vocal cord fixation. Reviewed International journal

Masayuki Okumura, Atsushi Motegi, Sadamoto Zenda, Naoki Nakamura, Hidehiro Hojo, Masaki Nakamura, Yasuhiro Hirano, Shun-Ichiro Kageyama, Satoko Arahira, Raturi Vijay Parshuram, Hirofumi Kuno, Ryuichi Hayashi, Makoto Tahara, Yoshiyuki Itoh, Shinji Naganawa, Tetsuo Akimoto

Head & neck Vol. 42 ( 8 ) page： 1775 - 1782 2020.8

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: The purpose of this study was to evaluate accelerated fractionated radiotherapy (AFRT) without elective nodal irradiation (ENI) for T3N0 glottic cancer (GC) without vocal cord fixation, especially in comparison with chemoradiotherapy (CRT) and hyperfractionated radiotherapy (HFRT) both of which included ENI. METHODS: The medical charts of patients with T3N0GC without cord fixation received definitive radiotherapy between June 2005 and March 2018 were reviewed. RESULTS: A total of 74 patients were analyzed. After a median follow-up time of 46 months (range, 12-141), 3-year local failure in AFRT/CRT/HFRT (n = 41/10/23) was 10%/20%/26%, 3-year regional failure 6%/0%/9%, 3-year progression-free survival 71%/69%/74%, and 3-year overall survival 77%/100%/87%. There were no significant differences among three groups in recurrence or survival. Grade 3 adverse events (AEs) were noted in 5/2/8 patients (12%/20%/35%) in AFRT/CRT/HFRT, respectively. There were no Grade 4/5 AEs. CONCLUSIONS: AFRT without ENI is an effective and feasible treatment for T3N0GC without cord fixation.

DOI： 10.1002/hed.26092

ロボット支援前立腺全摘除術後の難治性乳び腹水に対してリンパ管塞栓術が奏功した一例 Reviewed

兵藤良太, 山田恵一郎, 堀口瞭太, 伊藤準, 松島正哉, 駒田智大, 大脇貴之, 竹原康雄, 長縄慎二

日本インターベンショナルラジオロジー学会雑誌 Vol. 35 ( Suppl. ) page： 290 - 290 2020.8

Effects of endolymphatic hydrops on acoustic energy absorbance. Reviewed International journal

Masumi Kobayashi, Tadao Yoshida, Satofumi Sugimoto, Mariko Shimono, Masaaki Teranishi, Shinji Naganawa, Michihiko Sone

Acta oto-laryngologica Vol. 140 ( 8 ) page： 626 - 631 2020.7

Language：English Publishing type：Research paper (scientific journal)

Background: The presence of endolymphatic hydrops (EH) may cause hearing loss and affect the transmission of acoustic energy to the inner ear.Objectives: Acoustic energy absorbance on wideband acoustic immittance (WAI) was evaluated, focusing especially on EH in the vestibule.Material and methods: A total of 32 ears from 16 patients who underwent 3-T magnetic resonance imaging (MRI) to evaluate the presence of EH were examined, retrospectively. The degree of EH in the vestibule was classified into three grades (no, mild, and significant), and pure tone audiometry (PTA) and WAI were measured before and after a glycerol drip.Results: Ears with significant EH showed significantly higher hearing levels and air-bone gaps (ABG), and higher absorbance values on WAI at low frequencies (560-600 Hz) than ears with mild or no EH. Changes in absorbance values were observed in some ears without threshold change on PTA.Conclusions and Significance: This study showed significantly higher absorbance values of acoustic energy with significant vestibular EH at low frequencies. Considering ABGs observed in ears with significant EH, the presence of EH in the vestibule might cause an obstacle to the transmission of acoustic energy to the inner ear.

DOI： 10.1080/00016489.2020.1754460

A phase I/II trial of intraoperative breast radiotherapy in an Asian population: 10-year results with critical evaluation. Reviewed International journal

Mariko Kawamura, Yoshiyuki Itoh, Takeshi Kamomae, Masataka Sawaki, Toyone Kikumori, Nobuyuki Tsunoda, Junji Ito, Yoshie Shimoyama, Hiroko Satake, Shinji Naganawa

Journal of radiation research Vol. 61 ( 4 ) page： 602 - 607 2020.7

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

Although phase III trials have been published comparing whole breast irradiation (WBI) with accelerated partial breast irradiation (APBI) using intraoperative radiotherapy (IORT), long-term follow-up results are lacking. We report the 10-year follow-up results of a prospective phase I/II clinical trial of IORT. The inclusion criteria were as follows: (i) tumor size <2.5 cm, (ii) desire for breast-conserving surgery, (iii) age >50 years, (iv) negative margins after resection and (v) sentinel lymph node-negative disease. A single dose of IORT (19-21 Gy) was delivered to the tumor bed in the operation room just after wide local excision of the primary breast cancer using a 6-12 MeV electron beam. Local recurrence was defined as recurrence or new disease within the treated breast and was evaluated annually using mammography and ultrasonography. A total of 32 patients were eligible for evaluation. The median patient age was 65 years and the median follow-up time was 10 years. Two patients experienced local recurrence just under the nipple, out of the irradiated field, after 8 years of follow-up. Three patients had contralateral breast cancer and one patient experienced bone metastasis after 10 years of follow-up. No patient experienced in-field recurrence nor breast cancer death. Eight patients had hypertrophic scarring at the last follow-up. There were no lung or heart adverse effects. This is the first report of 10-year follow-up results of IORT as APBI. The findings suggest that breast cancer with extended intraductal components should be treated with great caution.

DOI： 10.1093/jrr/rraa029

Evaluation of segment 4 portal vein embolization added to right portal vein for right hepatic trisectionectomy: a retrospective propensity score-matched study. Reviewed

Jun Ito, Tomohiro Komada, Kojiro Suzuki, Masaya Matsushima, Masahiro Nakatochi, Yumiko Kobayashi, Tomoki Ebata, Shinji Naganawa, Masato Nagino

Journal of hepato-biliary-pancreatic sciences Vol. 27 ( 6 ) page： 299 - 306 2020.6

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Adding segment 4 (S4) portal vein embolization (PVE) to right PVE before right hepatic trisectionectomy is controversial. We retrospectively examined the effect of S4 PVE on segments 2 and 3 (S2+3) hypertrophy. METHODS: We reviewed patients with biliary carcinoma who underwent right PVE with (R3PVE) or without (R2PVE) S4 PVE using gelatin sponge particles and coils (2010-2019). Propensity score matching balanced the cohort for baseline characteristics, including total liver volume and S2+3 volume before PVE. We compared the groups regarding the S2+3 volume changes after PVE. RESULTS: Of 178 enrolled patients, 38 underwent R3PVE for right hepatic trisectionectomy and 140 underwent R2PVE for right hepatectomy. Twenty-eight patients from each group were respectively matched. The median absolute volume increase in (146 cm3 vs 70 cm3 ), hypertrophy rate of (52.4% vs 32.3%), and kinetic growth rate of (3.1 %/week vs 2.0 %/week) S2+3 were significantly higher in the R3PVE group than in the R2PVE group. In the pre-matched cohort, the rate of posthepatectomy liver failure and postoperative hospital stay did not significantly differ between the patients who underwent right hepatic trisectionectomy and right hepatectomy. CONCLUSION: R3PVE increased the S2+3 volume more effectively than R2PVE in patients with biliary carcinoma.

DOI： 10.1002/jhbp.723

Unexpected radioactive iodine accumulation on whole-body scan after I-131 ablation therapy for differentiated thyroid cancer. Reviewed

Shingo Iwano, Shinji Ito, Shinichiro Kamiya, Rintaro Ito, Katsuhiko Kato, Shinji Naganawa

Nagoya journal of medical science Vol. 82 ( 2 ) page： 205 - 215 2020.5

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

We retrospectively evaluated the frequency of unexpected accumulation of radioactive iodine on the post-therapy whole-body scan (Rx-WBS) after radioactive iodine (RAI) ablation therapy in patients with differentiated thyroid cancer (DTC). We searched our institutional database for Rx-WBSs of DTC patients who underwent RAI ablation or adjuvant therapy between 2012 and 2019. Patients with distant metastasis diagnosed by CT or PET/CT before therapy, and those had previously received RAI therapy were excluded. In total, 293 patients (201 female and 92 male, median age 54 years) were selected. Two nuclear medicine physicians interpreted the Rx-WBS images by determining the visual intensity of radioiodine uptake by the thyroid bed, cervical and mediastinal lymph nodes, lungs, and bone. Clinical features of the patients with and without the metastatic accumulation were compared by chi-square test and median test. Logistic regression analyses were performed to compare the association between the presence of metastatic accumulation and these clinical factors. Eighty-four of 293 patients (28.7%) showed metastatic accumulation. Patients with metastatic RAI accumulation showed a significantly higher frequency of pathological N1 (pN1) and serum thyroglobulin (Tg) > 1.5 ng/ml under TSH stimulation (p = 0.035 and p = 0.031, respectively). Logistic regression analysis indicated that a serum Tg > 1.5 ng/ml was significantly correlated with the presence of metastatic accumulation (odds ratio = 1.985; p = 0.033). In conclusion, Patients with Tg > 1.5 ng/ml were more likely to show metastatic accumulation. In addition, the presence of lymph node metastasis at the initial thyroid surgery was also associated with this unexpected metastatic accumulation.

DOI： 10.18999/nagjms.82.2.205

特集　基礎から学ぶ肺癌診断　　肺癌の3次元CT・PET/CT診断―原発巣の診断と悪性度― Reviewed

岩野信吾、伊藤信嗣、伊藤倫太郎、神谷晋一朗、加藤克彦、長縄慎二

画像診断 Vol. 40 ( 5 ) page： 439 - 446 2020.5

150周年記念記事　高次医用科学　創基150周年に寄せて Reviewed

長縄慎二

名大医学部学友時報 Vol. 843 ( - ) page： 10 - 10 2020.4

Evaluation of newly implemented dose calculation algorithms for multileaf collimator-based CyberKnife tumor-tracking radiotherapy. Reviewed International journal

Kohei Kawata, Takeshi Kamomae, Hiroshi Oguchi, Fumitaka Kawabata, Kuniyasu Okudaira, Mariko Kawamura, Kazuhiro Ohtakara, Yoshiyuki Itoh, Shinji Naganawa

Medical physics Vol. 47 ( 3 ) page： 1391 - 1403 2020.3

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: In the previous treatment planning system (TPS) for CyberKnife (CK), multileaf collimator (MLC)-based treatment plans could be created only by using the finite-size pencil beam (FSPB) algorithm. Recently, a new TPS, including the FSPB with lateral scaling option (FSPB+) and Monte Carlo (MC) algorithms, was developed. In this study, we performed basic and clinical end-to-end evaluations for MLC-based CK tumor-tracking radiotherapy using the MC, FSPB+, and FSPB. METHODS: Water- and lung-equivalent slab phantoms were combined to obtain the percentage depth dose (PDD) and off-center ratio (OCR). The CK M6 system and Precision TPS were employed, and PDDs and OCRs calculated by the MC, FSPB+, and FSPB were compared with the measured doses obtained for 30.8 × 30.8 mm2 and 60.0 × 61.6 mm2 fields. A lung motion phantom was used for clinical evaluation and MLC-based treatment plans were created using the MC. The doses were subsequently recalculated using the FSPB+ and FSPB, while maintaining the irradiation parameters. The calculated doses were compared with the doses measured using a microchamber (for target doses) or a radiochromic film (for dose profiles). The dose volume histogram (DVH) indices were compared for all plans. RESULTS: In homogeneous and inhomogeneous phantom geometries, the PDDs calculated by the MC and FSPB+ agreed with the measurements within ±2.0% for the region between the surface and a depth of 250 mm, whereas the doses calculated by the FSPB in the lung-equivalent phantom region were noticeably higher than the measurements, and the maximum dose differences were 6.1% and 4.4% for the 30.8 × 30.8 mm2 and 60.0 × 61.6 mm2 fields, respectively. The maximum distance to agreement values of the MC, FSPB+, and FSPB at the penumbra regions of OCRs were 1.0, 0.6, and 1.1 mm, respectively, but the best agreement was obtained between the MC-calculated curve and measurements at the boundary of the water- and lung-equivalent slabs, compared with those of the FSPB+ and FSPB. For clinical evaluations using the lung motion phantom, under the static motion condition, the dose errors measured by the microchamber were -1.0%, -1.9%, and 8.8% for MC, FSPB+, and FSPB, respectively; their gamma pass rates for the 3%/2 mm criterion comparing to film measurement were 98.4%, 87.6%, and 31.4% respectively. Under respiratory motion conditions, there was no noticeable decline in the gamma pass rates. In the DVH indices, for most of the gross tumor volume and planning target volume, significant differences were observed between the MC and FSPB, and between the FSPB+ and FSPB. Furthermore, significant differences were observed for lung Dmean , V15 Gy , and V20 Gy between the MC, FSPB+, and FSPB. CONCLUSIONS: The results indicate that the doses calculated using the MC and FSPB+ differed remarkably in inhomogeneous regions, compared with the FSPB. Because the MC was the most consistent with the measurements, it is recommended for final dose calculations in inhomogeneous regions such as the lung. Furthermore, the sufficient accuracy of dose delivery using MLC-based tumor-tracking radiotherapy by CK was demonstrated for clinical implementation.

DOI： 10.1002/mp.14013

Pharmacologic and non-pharmacologic interventions to prevent hypersensitivity reactions of non-ionic iodinated contrast media: a systematic review protocol Reviewed

Hiroyasu Umakoshi, Takashi Nihashi, Hironori Shimamoto, Takehiro Yamada, Hiroaki Ishiguchi, Akira Takada, Naoki Hirasawa, Shunichi Ishihara, Yasuo Takehara, Shinji Naganawa, Matthew Davenport, Teruhiko Terasawa

BMJ OPEN Vol. 10 ( 3 ) page： e033023 2020.3

Language：English Publishing type：Research paper (scientific journal) Publisher：BMJ PUBLISHING GROUP

Introduction Iodinated contrast media are commonly used in medical imaging and can cause hypersensitivity reactions, including rare but severe life-threatening reactions. Although several prophylactic approaches have been proposed for severe reactions, their effects remain unclear. Therefore, we aim to review systematically the preventive effects of pharmacologic and non-pharmacologic interventions and predictors of acute, hypersensitivity reactions.Methods and analysis We will search the PubMed, EMBASE and Cochrane Central Register of Controlled Trials databases from 1 January 1990 through 31 December 2019 and will examine the bibliographies of eligible studies, pertinent review articles and clinical practice guidelines. We will include prospective and retrospective studies of any design that evaluated the effects of pharmacological and non-pharmacological preventive interventions for adverse reactions of non-ionic iodinated contrast media. Two assessors will independently extract the characteristics of the study and intervention and the quantitative results. Two independent reviewers will assess the risk of bias using standard design-specific validity assessment tools. The primary outcome will be reduction in acute contrast media-induced hypersensitivity reactions. The secondary outcomes will include characteristics associated with the development of contrast media-induced acute hypersensitivity reactions, and adverse events associated with specific preventive interventions. Unique premedication regimens (eg, dose, drug and duration) and non-pharmacological strategies will be analysed separately. Average-risk and high-risk patients will be considered separately. A meta-analysis will be performed if appropriate.Ethics and dissemination Ethics approval is not applicable, as this will be a secondary analysis of publicly available data. The results of the analysis will be submitted for publication in a peer reviewed journal.

DOI： 10.1136/bmjopen-2019-033023

【基礎から学ぶ肺癌診断】肺癌の3次元CT・PET/CT診断原発巣の診断と悪性度 Reviewed

磁気共鳴画像によるNeurofluids動態の解明 Reviewed

長縄慎二、田岡俊昭、川井　恒

脳とこころの研究センター脳疾患克服に向けた次世代創薬開発のためのコホート・コンソーシアム型研究拠点形成令和元年度活動報告書 Vol. - ( - ) page： 30 - 30 2020.3

脳動脈瘤破裂リスク評価のための磁気共鳴流体解析と計算流体解析による形態ならびに血流動態バイオマーカーの検討 Reviewed

MAJUWANA GAMAGE,　礒田治夫、泉　孝嗣、若林俊彦、長縄慎二

脳とこころの研究センター脳疾患克服に向けた次世代創薬開発のためのコホート・コンソーシアム型研究拠点形成令和元年度活動報告書 Vol. - ( - ) page： 27 - 27 2020.3

岩野信吾, 伊藤信嗣, 伊藤倫太郎, 神谷晋一朗, 加藤克彦, 長縄慎二

画像診断 Vol. 40 ( 5 ) page： 439 - 446 2020.3

Authorship：Last author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：(株)Gakken

＜文献概要＞肺癌の臨床病期分類(TNM分類)は主に画像診断に基づいて行われる.2017年に改訂されたTNM分類では,T因子(サイズ)の診断が複雑になった.病理学的浸潤径に相当する充実成分径の計測はthinsection CTで行うのが基本であるが,3次元CTやPET/CTを利用することで精度の向上が期待できる.

Other Link： https://search-tp.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2020&ichushi_jid=J00235&link_issn=&doc_id=20200408090014&doc_link_id=10.15105%2FGZ.0000001656&url=https%3A%2F%2Fdoi.org%2F10.15105%2FGZ.0000001656&type=%88%E3%8F%91.jp_%83I%81%5B%83%8B%83A%83N%83Z%83X&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00024_2.gif

White matter microstructural changes in tuberous sclerosis: Evaluation by neurite orientation dispersion and density imaging (NODDI) and diffusion tensor images. Reviewed International journal

Toshiaki Taoka, Noriko Aida, Yuta Fujii, Kazushi Ichikawa, Hisashi Kawai, Toshiki Nakane, Rintaro Ito, Shinji Naganawa

Scientific reports Vol. 10 ( 1 ) page： 436 - 436 2020.1

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

Neurite orientation dispersion and density imaging (NODDI) is a novel diffusion method for evaluating tissue microstructure, and may provide additional information over conventional diffusion tensor imaging (DTI). We evaluated NODDI and DTI parameters in cases of tuberous sclerosis (TS) to assess microstructural changes in the white matter. Eleven cases of tuberous sclerosis and eight age-matched controls underwent NODDI and DTI. We performed qualitative analysis and tract-based spatial statistics (TBSS) analysis of the NODDI parameters (Ficv: intracellular volume fraction, Fiso: isotropic fraction, ODI: orientation dispersion index) as well as DTI parameters (MD: mean diffusivity, FA: fractional anisotropy). We also performed a correlation analysis between clinical symptoms and parameters. The qualitative analysis indicated that the Ficv had a lower value in TS cases particularly in the tubers adjacent to the white matter. The TBSS analysis showed that the TS cases had decreased Ficv in a greater area compared to the other parameters including MD. In particular, the Ficv was decreased in deep white matter, such as the superior longitudinal fascicles (SLF). The application of NODDI to TS cases revealed tissue microstructural changes, and particularly the Ficv could detect more widespread abnormalities in white matter structure compared to DTI parameters.

DOI： 10.1038/s41598-019-57306-w

Glymphatic imaging using MRI. Reviewed International journal

Toshiaki Taoka, Shinji Naganawa

Journal of magnetic resonance imaging : JMRI Vol. 51 ( 1 ) page： 11 - 24 2020.1

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

In recent years, the existence of a mass transport system in the brain via cerebrospinal fluid (CSF) or interstitial fluid (ISF) has been suggested by many studies. The glymphatic system is hypothesized to be a waste clearance system of the CSF through the perivascular and interstitial spaces in the brain. Tracer studies have primarily been used to visualize or evaluate the waste clearance system in the brain, and evidence for this system has accumulated. The initial study that identified the glymphatic system was an in vivo tracer study in mice. In that study, fluorescent tracers were injected into the cisterna magna and visualized by two-photon microscopy. MRI has also been used to evaluate glymphatic function primarily with gadolinium-based contrast agents (GBCAs) as tracers. A number of GBCA studies evaluating glymphatic function have been conducted using either intrathecal or intravenous injections. Stable isotopes, such as 17 O-labeled water, may also be used as tracers since they can be detected by MRI. In addition to tracer studies, several other approaches have been used to evaluate ISF dynamics within the brain, including diffusion imaging. Phase contrast evaluation is a powerful method for visualizing flow within the CSF space. In order to evaluate the movement of water within tissue, diffusion-weighted MRI represents another promising technique, and several studies have utilized diffusion techniques for the evaluation of the glymphatic system. This review will discuss the findings of these diffusion studies. Level of Evidence: 5 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019. J. Magn. Reson. Imaging 2020;51:11-24.

DOI： 10.1002/jmri.26892

中枢神経系原発anaplastic lymphoma kinase陽性未分化大細胞リンパ腫の1例 Reviewed

Celebrating the beginning of international journal collaboration. Reviewed

Shinji Naganawa, Yukunori Korogi

Japanese journal of radiology Vol. 38 ( 1 ) page： 1 - 2 2020.1

佐々木裕太郎, 中道玲瑛, 伊藤信嗣, 川井恒, 岩野信吾, 田岡俊昭, 加藤克彦, 川島直美, 下山芳江, 長縄慎二

映像情報Medical Vol. 52 ( 1 ) page： 82 - 83 2020.1

Quantification of Endolymphatic Space Volume after Intravenous Administration of a Single Dose of Gadolinium-based Contrast Agent: 3D-real Inversion Recovery versus HYDROPS-Mi2. Reviewed

Toshio Ohashi, Shinji Naganawa, Ai Takeuchi, Toshio Katagiri, Kayao Kuno

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 19 ( 2 ) page： 119 - 124 2020

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Recently, the use of 3D real inversion recovery (3D-real IR) imaging has been proposed for the evaluation of endolymphatic hydrops (EH). This method shows similar contrast between the endolymphatic and perilymphatic spaces and surrounding bone compared with the hybrid of reversed image of positive endolymph signal and native image of perilymph signal multiplied with heavily T2-weighted MR cisternography (HYDROPS-Mi2) image. We measured the volume of the endolymphatic space using 3D-real IR and HYDROPS-Mi2 images, and compared the measurements obtained with both techniques. METHODS: HYDROPS-Mi2 and 3D-real IR images were obtained for 30 ears from 15 patients with clinical suspicion of EH; imaging was performed 4 h after intravenous administration of a single dose of gadolinium-based contrast agent. We measured the volume of the endolymphatic space in the cochlea and vestibule by manually drawing the regions of interest. The correlation between endolymphatic volume determined from HYDROPS-Mi2 images and 3D-real IR images was calculated. RESULTS: There was a strong positive linear correlation between the cochlear and vestibular endolymphatic volume determined from HYDROPS-Mi2 and 3D-real IR images. The Spearman's rank correlation coefficient (ρ) between the measurements obtained with both images was 0.805 (P < 0.001) for the cochlea and 0.826 (P < 0.001) for the vestibule. CONCLUSION: The endolymphatic volume measured using 3D-real IR images strongly correlated with that measured using HYDROPS-Mi2 images. Thus, 3D-real IR imaging might be a suitable method for the measurement of endolymphatic volume.

DOI： 10.2463/mrms.mp.2019-0013

The Space between the Pial Sheath and the Cortical Venous Wall May Connect to the Meningeal Lymphatics. Reviewed

Shinji Naganawa, Rintaro Ito, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 19 ( 1 ) page： 1 - 4 2020

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

We currently obtain pre- and post-contrast enhanced whole brain 3D-real inversion recovery images for the evaluation of endolymphatic hydrops. We noticed that the space between the pial sheath surrounding the cortical veins and the cortical venous wall is enhanced and this enhancement seems to connect to the meningeal lymphatics along superior sagittal sinus. This new anatomical concept regarding the outflow from the glymphatic system might be important for the future research in neuroscience.

DOI： 10.2463/mrms.bc.2019-0099

Detection of IV-gadolinium Leakage from the Cortical Veins into the CSF Using MR Fingerprinting. Reviewed

Shinji Naganawa, Toshiki Nakane, Hisashi Kawai, Toshiaki Taoka, Hirokazu Kawaguchi, Katsuya Maruyama, Katsutoshi Murata, Gregor Körzdörfer, Josef Pfeuffer, Mathias Nittka, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 19 ( 2 ) page： 141 - 146 2020

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: It has been reported that leakage of intravenously administered gadolinium-based contrast agents (IV-GBCAs) into the cerebrospinal fluid (CSF) from the cortical veins even in healthy subjects can be detected using a highly sensitive pulse sequence such as heavily T2-weighted 3D fluid-attenuated inversion recovery and 3D-real inversion recovery (IR). The purpose of this study was to evaluate the feasibility of MR fingerprinting to detect GBCA leakage from the cortical veins after IV-GBCA. MATERIALS: Fourteen patients with suspected endolymphatic hydrops (EH) who received a single dose of IV-GBCA (39-79 years old) were included. The real IR images as well as MR fingerprinting images were obtained at 4 h after IV-GBCA. T1 and T2 values were obtained using MR fingerprinting and analyzed in ROIs covering intense GBCA leakage, and non-leakage areas of the CSF as determined on real IR images. The scan time for real IR imaging was 10 min and that for MR fingerprinting was 41 s. RESULTS: The mean T1 value of the ROI in the area of GBCA leakage was 2422 ± 261 ms and that in the non-leakage area was 3851 ± 235 ms (P < 0.01). There was no overlap between the T1 values in the area of GBCA leakage and those in the non-leakage area.The mean T2 value in the area of GBCA leakage was 319 ± 90 ms and that in the non-leakage area was 670 ± 166 ms (P < 0.01). There was some overlap between the T2 values in the area of GBCA leakage and those in the non-leakage area. CONCLUSION: Leaked GBCA from the cortical veins into the surrounding CSF can be detected using MR fingerprinting obtained in <1 min.

DOI： 10.2463/mrms.mp.2019-0048

Confirmation of Age-dependence in the Leakage of Contrast Medium around the Cortical Veins into Cerebrospinal Fluid after Intravenous Administration of Gadolinium-based Contrast Agent. Reviewed

Shinji Naganawa, Rintaro Ito, Hisashi Kawai, Toshiaki Taoka, Tadao Yoshida, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 19 ( 4 ) page： 375 - 381 2020

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: It has been reported previously that intravenously administered gadolinium-based contrast agent (GBCA) leaks into the subarachnoid space around the cortical veins at 4 h after injection in all old people over 37 years, but not in younger people up to 37 years of age in 3D-real IR images. The purpose of this study was to investigate whether there was a strict threshold of 37 years of age for the leakage of the GBCA into the subarachnoid space. METHODS: The subjects included 190 patients, that were scanned for 3D-real IR images at 4 hours after intravenous injection of GBCA as a diagnostic test for endolymphatic hydrops. The patient's age ranged from 14 to 81 years. Two experienced neuroradiologists evaluated the images to determine whether the GBCA leakage around the cortical veins was positive or negative. Any discrepancies between the two observers were discussed and a consensus was obtained.A Mann-Whitney U test and receiver operating characteristic (ROC) curve analysis were used to compare the positive and the negative group and to set the age cut-off value for the prediction of GBCA leakage. RESULTS: The GBCA leakage around the cortical veins was negative in 35 patients and positive in 155 patients. The average age was 33 ± 11 years in the negative group, and 55 ± 12 years in the positive group (P < 0.01). In the ROC analysis for the age and leakage of the GBCA, an area under the curve was 0.905 and the cut-off age was 37.317 years (sensitivity of 0.942 and specificity of 0.771). CONCLUSION: Intravenously administered GBCA leaks into the subarachnoid space around the cortical veins in most patients over 37 years of age. However, it should be noted that it can be found occasionally in patients under 37 years of age.

DOI： 10.2463/mrms.mp.2019-0182

Comprehensive Evaluation of B1+-corrected FISP-based Magnetic Resonance Fingerprinting: Accuracy, Repeatability and Reproducibility of T1 and T2 Relaxation Times for ISMRM/NIST System Phantom and Volunteers. Reviewed

Yutaka Kato, Kazushige Ichikawa, Kuniyasu Okudaira, Toshiaki Taoka, Hirokazu Kawaguchi, Katsutoshi Murata, Katsuya Maruyama, Gregor Koerzdoerfer, Josef Pfeuffer, Mathias Nittka, Shinji Naganawa

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 19 ( 3 ) page： 168 - 175 2020

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: This study aimed to evaluate comprehensively; accuracy, repeatability and reproducibility of T1 and T2 relaxation times measured by magnetic resonance fingerprinting using B1+-corrected fast imaging with steady-state precession (FISP-MRF). METHODS: The International Society of Magnetic Resonance in Medicine/National Institute of Standards and Technology (ISMRM/NIST) phantom was scanned for 100 days, and six healthy volunteers for 5 days using a FISP-MRF prototype sequence. Accuracy was evaluated on the phantom by comparing relaxation times measured by FISP-MRF with the reference values provided by the phantom manufacturer. Daily repeatability was characterized as the coefficient of variation (CV) of the measurements over 100 days for the phantom and over 5 days for volunteers. In addition, the cross-scanner reproducibility was evaluated in volunteers. RESULTS: In the phantom study, T1 and T2 values from FISP-MRF showed a strong linear correlation with the reference values of the phantom (R2 = 0.9963 for T1; R2 = 0.9966 for T2). CVs were <1.0% for T1 values larger than 300 ms, and <3.0% for T2 values across a wide range. In the volunteer study, CVs for both T1 and T2 values were <5.0%, except for one subject. In addition, all T2 values estimated by FISP-MRF in vivo were lower than those measured with conventional mapping sequences reported in previous studies. The cross-scanner variation of T1 and T2 showed good agreement between two different scanners in the volunteers. CONCLUSION: B1+-corrected FISP-MRF showed an acceptable accuracy, repeatability and reproducibility in the phantom and volunteer studies.

DOI： 10.2463/mrms.mp.2019-0016

Assessing the Risk of Intracranial Aneurysm Rupture Using Morphological and Hemodynamic Biomarkers Evaluated from Magnetic Resonance Fluid Dynamics and Computational Fluid Dynamics. Reviewed

Roshani Perera, Haruo Isoda, Kenta Ishiguro, Takashi Mizuno, Yasuo Takehara, Masaki Terada, Chiharu Tanoi, Takehiro Naito, Harumi Sakahara, Hisaya Hiramatsu, Hiroki Namba, Takashi Izumi, Toshihiko Wakabayashi, Takafumi Kosugi, Yuki Onishi, Marcus Alley, Yoshiaki Komori, Mitsuru Ikeda, Shinji Naganawa

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 19 ( 4 ) page： 333 - 344 2020

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Evaluate in vivo hemodynamic and morphological biomarkers of intracranial aneurysms, using magnetic resonance fluid dynamics (MRFD) and MR-based patient specific computational fluid dynamics (CFD) in order to assess the risk of rupture. METHODS: Forty-eight intracranial aneurysms (10 ruptured, 38 unruptured) were scrutinized for six morphological and 10 hemodynamic biomarkers. Morphological biomarkers were calculated based on 3D time-of-flight magnetic resonance angiography (3D TOF MRA) in MRFD analysis. Hemodynamic biomarkers were assessed using both MRFD and CFD analyses. MRFD was performed using 3D TOF MRA and 3D cine phase-contrast magnetic resonance imaging (3D cine PC MRI). CFD was performed utilizing patient specific inflow-outflow boundary conditions derived from 3D cine PC MRI. Univariate analysis was carried out to identify statistically significant biomarkers for aneurysm rupture and receiver operating characteristic (ROC) analysis was performed for the significant biomarkers. Binary logistic regression was performed to identify independent predictive biomarkers. RESULTS: Morphological biomarker analysis revealed that aneurysm size [P = 0.021], volume [P = 0.035] and size ratio [P = 0.039] were statistically significantly different between the two groups. In hemodynamic biomarker analysis, MRFD results indicated that ruptured aneurysms had higher oscillatory shear index (OSI) [OSI.max, P = 0.037] and higher relative residence time (RRT) [RRT.ave, P = 0.035] compared with unruptured aneurysms. Correspondingly CFD analysis demonstrated significant differences for both average and maximum OSI [OSI.ave, P = 0.008; OSI.max, P = 0.01] and maximum RRT [RRT.max, P = 0.045]. ROC analysis revealed AUC values greater than 0.7 for all significant biomarkers. Aneurysm volume [AUC, 0.718; 95% CI, 0.491-0.946] and average OSI obtained from CFD [AUC, 0.774; 95% CI, 0.586-0.961] were retained in the respective logistic regression models. CONCLUSION: Both morphological and hemodynamic biomarkers have significant influence on intracranial aneurysm rupture. Aneurysm size, volume, size ratio, OSI and RRT could be potential biomarkers to assess aneurysm rupture risk.

DOI： 10.2463/mrms.mp.2019-0107

Kinetic volume analysis on dynamic contrast-enhanced MRI of triple-negative breast cancer: associations with survival outcomes. Reviewed International journal

Yoko Hayashi, Hiroko Satake, Satoko Ishigaki, Rintaro Ito, Mariko Kawamura, Hisashi Kawai, Shingo Iwano, Shinji Naganawa

The British journal of radiology Vol. 93 ( 1106 ) page： 20190712 - 20190712 2020

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: To evaluate the associations between computer-aided diagnosis (CAD)-generated kinetic volume parameters and survival in triple-negative breast cancer (TNBC) patients. METHODS: 40 patients with TNBC who underwent pre-operative MRI between March 2008 and March 2014 were included. We analyzed CAD-generated parameters on dynamic contrast-enhanced MRI, visual MRI assessment, and histopathological data. Cox proportional hazards models were used to determine associations with survival outcomes. RESULTS: 12 of the 40 (30.0%) patients experienced recurrence and 7 died of breast cancer after a median follow-up of 73.6 months. In multivariate analysis, higher percentage volume (%V) with more than 200% initial enhancement rate correlated with worse disease-specific survival (hazard ratio, 1.12; 95% confidence interval, 1.02-1.22; p-value, 0.014) and higher %V with more than 100% initial enhancement rate followed by persistent curve type at 30% threshold correlated with worse disease-specific survival (hazard ratio, 1.33; 95% confidence interval, 1.10-1.61; p-value, 0.004) and disease-free survival (hazard ratio, 1.27; 95% confidence interval, 1.12-1.43; p-value, 0.000). CONCLUSION: CAD-generated kinetic volume parameters may correlate with survival in TNBC patients. Further study would be necessary to validate our results on larger cohorts. ADVANCES IN KNOWLEDGE: CAD generated kinetic volume parameters on breast MRI can predict recurrence and survival outcome of patients in TNBC. Varying the enhancement threshold improved the predictive performance of CAD generated kinetic volume parameter.

DOI： 10.1259/bjr.20190712

Optimal Plane Selection for Measuring Post-prandial Blood Flow Increase within the Superior Mesenteric Artery: Analysis Using 4D Flow and Computational Fluid Dynamics. Reviewed

Masataka Sugiyama, Yasuo Takehara, Masanori Kawate, Naoki Ooishi, Masaki Terada, Haruo Isoda, Harumi Sakahara, Shinji Naganawa, Kevin M Johnson, Oliver Wieben, Tetsuya Wakayama, Atsushi Nozaki, Hiroyuki Kabasawa

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 19 ( 4 ) page： 366 - 374 2020

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: 2D cine phase contrast (PC)-MRI is a standard velocimetry for the superior mesenteric artery (SMA); however, the optimal localization of the measurement plane has never been fully discussed previously. The purpose of this Institutional Review Board approved prospective and single arm study is to test whether flow velocimetry of the SMA with combined use of 2D cine PC-MRI and meal challenge is dependent on the localizations of the measurement planes and to seek optimal section for velocimetry. METHODS: Seven healthy volunteers underwent cardiac phase resolved ECG gated 2D cine PC-MRI pre- and 30 min post-meal challenge at three measurement planes: proximal, curved mid section and distal straight section of the SMA at 3T. 4D Flow using 3D cine PC-MRI with vastly undersampled isotropic projection imaging (PC VIPR) was also performed right after 2D cine PC-MRI to delineate the flow dynamics within the SMA using streamline analysis. Two radiologists measured flow velocities, and rated the appearances of the abnormal flow in the SMA on streamlines derived from the 4D Flow and the computational fluid dynamics (CFD). RESULTS: 2D cine PC-MRI measured increased temporally averaged flow velocity (mm/s) after the meal challenge only in the proximal (129.3 vs. 97.8, P = 0.0313) and distal section (166.9 vs. 96.2, P = 0.0313), not in the curved mid section (113.1 vs. 85.5, P = 0.0625). The average velocities were highest and their standard errors (8.5-26.5) were smallest at the distal straight section both before and after the meal challenge as compared with other sections. The streamline analysis depicted more frequent appearances of vertical or helical flow in the curved mid section both on 4D Flow and CFD (κ: 0.27-0.68). CONCLUSION: SMA velocimetry with 2D cine PC-MRI was dependent on the localization of the measurement planes. Distal straight section, not in the curved mid section is recommended for MR velocimetry.

DOI： 10.2463/mrms.mp.2019-0089

Abnormal Flow Dynamics Result in Low Wall Shear Stress and High Oscillatory Shear Index in Abdominal Aortic Dilatation: Initial in vivo Assessment with 4D-flow MRI. Reviewed

Assessment of Severity in Chronic Thromboembolic Pulmonary Hypertension by Quantitative Parameters of Dual-Energy Computed Tomography Reviewed

Tsutsumi Yoshinori, Iwano Shingo, Okumura Naoki, Adachi Shiro, Abe Shinji, Kondo Takahisa, Kato Katsuhiko, Naganawa Shinji

JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Vol. 44 ( 4 ) page： 578 - 585 2020

Yasuo Takehara, Haruo Isoda, Mamoru Takahashi, Naoki Unno, Norihiko Shiiya, Takasuke Ushio, Satoshi Goshima, Shinji Naganawa, Marcus Alley, Tetsuya Wakayama, Atsushi Nozaki

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 19 ( 3 ) page： 235 - 246 2020

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: To characterize the non-laminar flow dynamics and resultant decreased wall shear stress (WSS) and high oscillatory shear index (OSI) of the infrarenal abdominal aortic dilatation, cardiac phase-resolved 3D phase-contrast MRI (4D-flow MRI) was performed. METHODS: The prospective single-arm study was approved by the Institutional Review Board and included 18 subjects (median 67.5 years) with the dilated infrarenal aorta (median diameter 35 mm). 4D-flow MRI was conducted on a 1.5T MRI system. On 3D streamline images, laminar and non-laminar (i.e., vortex or helical) flow patterns were visually assessed both for the dilated aorta and for the undilated upstream aorta. Cardiac phase-resolved flow velocities, WSS and OSI, were also measured for the dilated aorta and the upstream undilated aorta. RESULTS: Non-laminar flow represented by vortex or helical flow was more frequent and overt in the dilated aorta than in the undilated upstream aorta (P < 0.0156) with a very good interobserver agreement (weighted kappa: 0.82-1.0). The WSS was lower, and the OSI was higher on the dilated aortic wall compared with the proximal undilated segments. In mid-systole, mean spatially-averaged WSS was 0.20 ± 0.016 Pa for the dilated aorta vs. 0.68 ± 0.071 Pa for undilated upstream aorta (P < 0.0001), and OSI on the dilated aortic wall was 0.093 ± 0.010 vs. 0.041 ± 0.0089 (P = 0.013). The maximum values and the amplitudes of the WSS at the dilated aorta were inversely proportional to the ratio of dilated/undilated aortic diameter (r = -0.694, P = 0.0014). CONCLUSION: 4D-flow can characterize abnormal non-laminar flow dynamics within the dilated aorta in vivo. The wall of the infrarenal aortic dilatation is continuously and increasingly affected by atherogenic stimuli due to the flow disturbances represented by vortex or helical flow, which is reflected by lower WSS and higher OSI.

DOI： 10.2463/mrms.mp.2019-0188

ちょっと気になる胆・膵画像ティーチングファイルから(第43回) 術前診断が困難であった膵lymphangiomaの1例

2020年　最新医療機器の現状と展望　CTおよびMRIなどの画像診断装置の今後の在り方と展望 Reviewed

長縄慎二

月刊新医療データブック・シリーズ　医療機器システム白書 Vol. - ( - ) page： 12 - 15 2019.12

私と医療　New Med Essay ―第176回　動機はいい加減だったものの、真面目に取り組めばこそ― Reviewed

長縄慎二

月刊新医療 Vol. 540 ( - ) page： 77 - 77 2019.11

正常老化におけるTHK5351分布様式と安静時機能的ネットワークの関係性

吉田有佑, 横井孝政, 渡辺宏久, 山口博司, Bagarinao Epifanio, 桝田道人, 加藤隼康, 小倉礼, 大嶽れい子, 川畑和也, 原一洋, 勝野雅央, 加藤克彦, 長縄慎二, 岡村信行, 矢内一彦, 祖父江元

臨床神経学 Vol. 59 ( Suppl. ) page： S297 - S297 2019.11

Balloon-Occluded Retrograde Transvenous Obliteration for Fundal Gastric Variceal Bleeding in a Small Child. Reviewed International journal

Tomohiro Komada, Kojiro Suzuki, Kazuo Oshima, Masaya Matsushima, Ken Nagasaka, Shinji Naganawa

Journal of vascular and interventional radiology : JVIR Vol. 30 ( 10 ) page： 1624 - 1625 2019.10

小川浩, 竹原康雄, 長縄慎二, 高見秀樹, 中黒匡人

胆と膵 Vol. 40 ( 10 ) page： 841 - 844 2019.10

Glymphatic systemとMRI―ヒトでの可視化に向けた取り組み Reviewed

長縄慎二

医学のあゆみ Vol. 270 ( 13 ) page： 1189 - 1192 2019.10

Multi-window levels and widths imaging 画像変換による新たな読影手法の検討

伊藤倫太郎, 岩野信吾, 小田紘久, 森健策, 長縄慎二

日本医学放射線学会秋季臨床大会抄録集 Vol. 55回 page： S531 - S532 2019.9

Reorganization of brain networks and its association with general cognitive performance over the adult lifespan. Reviewed International journal

Epifanio Bagarinao, Hirohisa Watanabe, Satoshi Maesawa, Daisuke Mori, Kazuhiro Hara, Kazuya Kawabata, Noritaka Yoneyama, Reiko Ohdake, Kazunori Imai, Michihito Masuda, Takamasa Yokoi, Aya Ogura, Toshiaki Taoka, Shuji Koyama, Hiroki C Tanabe, Masahisa Katsuno, Toshihiko Wakabayashi, Masafumi Kuzuya, Norio Ozaki, Minoru Hoshiyama, Haruo Isoda, Shinji Naganawa, Gen Sobue

Scientific reports Vol. 9 ( 1 ) page： 11352 - 11352 2019.8

Language：English Publishing type：Research paper (scientific journal)

Healthy aging is associated with structural and functional changes in the brain even in individuals who are free of neurodegenerative diseases. Using resting state functional magnetic resonance imaging data from a carefully selected cohort of participants, we examined cross sectional changes in the functional organization of several large-scale brain networks over the adult lifespan and its potential association with general cognitive performance. Converging results from multiple analyses at the voxel, node, and network levels showed widespread reorganization of functional brain networks with increasing age. Specifically, the primary processing (visual and sensorimotor) and visuospatial (dorsal attention) networks showed diminished network integrity, while the so-called core neurocognitive (executive control, salience, and default mode) and basal ganglia networks exhibited relatively preserved between-network connections. The visuospatial and precuneus networks also showed significantly more widespread increased connectivity with other networks. Graph analysis suggested that this reorganization progressed towards a more integrated network topology. General cognitive performance, assessed by Addenbrooke's Cognitive Examination-Revised total score, was positively correlated with between-network connectivity among the core neurocognitive and basal ganglia networks and the integrity of the primary processing and visuospatial networks. Mediation analyses further indicated that the observed association between aging and relative decline in cognitive performance could be mediated by changes in relevant functional connectivity measures. Overall, these findings provided further evidence supporting widespread age-related brain network reorganization and its potential association with general cognitive performance during healthy aging.

DOI： 10.1038/s41598-019-47922-x

High-dose-rate intracavitary brachytherapy for recurrent cervical cancer in the vaginal stump after hysterectomy Reviewed Open Access

Kozai Yuka, Itoh Yoshiyuki, Kawamura Mariko, Nakahara Rie, Ito Junji, Okada Tohru, Kikkawa Fumitaka, Ikeda Mitsuru, Naganawa Shinji

NAGOYA JOURNAL OF MEDICAL SCIENCE Vol. 81 ( 3 ) page： 351 - 358 2019.8

Language：English Publishing type：Research paper (scientific journal)

This study aimed to evaluate the treatment outcomes of patients who received high-dose-rate intracavitary brachytherapy (HDR-BT) using Iridium-192 with or without external beam radiotherapy as definitive treatment for recurrent cervical cancer after hysterectomy. Thirty-six patients with local recurrence after hysterectomy received radiotherapy including HDR-BT from 2005 to 2013. Overall survival, local control rate, and progression-free survival were estimated retrospectively via the Kaplan-Meier method. Late adverse events were also scored using the Common Terminology Criteria for Adverse Events (version 3.0). Median follow-up time was 38 (range, 7.4-101.3) months. The 3-year estimates of overall survival, local control rate, and progression-free survival were 100.0%, 82.8%, and 76.8%, respectively. Two patients (5.6%) had grade 2 lymphedema, but no other adverse events greater than grade 2 were reported. In conclusion, HDR-BT was an effective treatment modality for patients with cervical cancer recurrence in the vaginal stump.

DOI： 10.18999/nagjms.81.3.351

Whole abdominopelvic intensity-modulated radiation therapy for peritoneal disseminated rhabdomyosarcoma with three-year follow-up: a case report. Reviewed International journal

Mariko Kawamura, Kuniyasu Okudaira, Yoshiyuki Itoh, Takeshi Kamomae, Eri Nishikawa, Hideki Muramatsu, Yoshiyuki Takahashi, Kazuki Yokota, Shinji Naganawa

Radiation oncology (London, England) Vol. 14 ( 1 ) page： 127 - 127 2019.7

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: The role of local radiotherapy in the treatment of metastatic rhabdomyosarcoma is important. However, with peritoneal dissemination, the application of local therapy is challenging. Although there are few reports addressing the efficacy of the whole abdominopelvic irradiation to peritoneal disseminated rhabdomyosarcoma patients, no precise curse of treatment nor the follow up result is explained in paper nor in the text. CASE PRESENTATION: Six years old rhabdomyosarcoma boy with peritoneal dissemination was treated at our facility under COG D9803 protocol (vincristine, dactinomycin, and cyclophosphamide (VAC)). He underwent tumor resection on the 14th week according to the protocol. During surgery, the 2-cm residual tumor was completely resected, but in the pelvis, numerous nodules that were suspected as peritoneal disseminated tumors were observed. We administered 30 Gy/20fr whole abdominopelvic radiotherapy using volumetric modulated arc therapy (VMAT) technique and a 6 Gy sequential boost to pelvis after the surgery and completed the protocol treatment. During the course of treatment, the patient experienced G4 hematological toxicity and received multiple transfusions, particularly after whole abdominopelvic irradiation. He has achieved complete remission and is alive without evidence of recurrence and severe late adverse effect for 3 years. In terms of growth, his height and weight are within the average values for Japanese boys at the same age. CONCLUSION: By using the VMAT technique, a patient with peritoneal disseminated rhabdomyosarcoma can be treated, and a dose of 30 Gy to the whole abdominopelvis with concurrent chemotherapy may be tolerable.

DOI： 10.1186/s13014-019-1333-x

2.胸部領域　胸部画像診断におけるAIと臨床研究について Reviewed

伊藤倫太郎、岩野信吾、長縄慎二

INNERVISION Vol. 34 ( 7 ) page： 25 - 28 2019.7

Postoperative recurrence of clinical early-stage non-small cell lung cancers: a comparison between solid and subsolid nodules. Reviewed International journal

Shingo Iwano, Hiroyasu Umakoshi, Shinichiro Kamiya, Kohei Yokoi, Koji Kawaguchi, Takayuki Fukui, Shinji Naganawa

Cancer imaging : the official publication of the International Cancer Imaging Society Vol. 19 ( 1 ) page： 33 - 33 2019.6

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: For subsolid non-small cell lung cancers (NSCLCs), solid size (SS), which is the maximal diameter of the solid component, correlates more accurately with tumor prognosis than the total size, which is the maximal diameter of the entire tumor, including ground-glass opacity. We reviewed the propriety of the TNM staging based on the SS for early-stage NSCLCs. METHODS: We retrospectively reviewed the preoperative radiological reports, clinical records, and pathological reports of NSCLC cases in our hospital between 2010 and 2013, and clinical stage (c-Stage) 0 and I tumors were selected. Disease-free survival (DFS), based on survival analysis, was used to assess the tumor characteristics that predicted the prognosis. RESULTS: A total of 247 NSCLC diagnoses in 231 patients (88 women and 143 men; age, 67 ± 7 years) were included in our cohort. They were classified into solid (n = 131) and subsolid (n = 116) nodules. The DFS curves indicated that prognosis was significantly worse in the following order: c-Stage 0, c-Stage IA, and c-Stage IB tumors (p = 0.016). Patients with solid nodules showed a significantly worse prognosis than patients with subsolid nodules (p < 0.001). A multivariate Cox proportional hazards model showed that the significant predictive factors for DFS were c-Stage (hazard ratio, 1.600; p = 0.020) and solid nodules (hazard ratio, 3.077; p = 0.031). CONCLUSIONS: For early-stage NSCLCs, the c-Stage based on the SS in subsolid nodules was useful for predicting postoperative DFS. In addition, whether nodules were solid or subsolid was another independent prognostic factor.

DOI： 10.1186/s40644-019-0219-3

Monitoring of fatigue in radiologists during prolonged image interpretation using fNIRS. Reviewed

Takashi Nihashi, Takeo Ishigaki, Hiroko Satake, Shinji Ito, Osamu Kaii, Yoshine Mori, Kazuhiro Shimamoto, Hiromichi Fukushima, Kojiro Suzuki, Hiroyasu Umakoshi, Mitsuo Ohashi, Fumio Kawaguchi, Shinji Naganawa

Japanese journal of radiology Vol. 37 ( 6 ) page： 437 - 448 2019.6

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: To determine whether functional near-infrared spectroscopy (fNIRS) allows monitoring fatigue in radiologists during prolonged image interpretation. MATERIALS AND METHODS: Nine radiologists participated as subjects in the present study and continuously interpreted medical images and generated reports for cases for more than 4 h under real clinical work conditions. We measured changes in oxygenated hemoglobin concentrations [oxy-Hb] in the prefrontal cortex using 16-channel fNIRS (OEG16ME, Spectratech) every hour during the Stroop task to evaluate fatigue of radiologists and recorded fatigue scale (FS) as a behavior data. RESULTS: Two subjects showed a subjective feeling of fatigue and an apparent decrease in brain activity after 4 h, so the experiment was completed in 4 h. The remaining seven subjects continued the experiment up to 5 h. FS decreased with time, and a significant reduction was observed between before and the end of image interpretation. Seven out of nine subjects showed a minimum [oxy-Hb] change at the end of prolonged image interpretation. The mean change of [oxy-Hb] at the end of all nine subjects was significantly less than the maximum during image interpretation. CONCLUSION: fNIRS using the change of [oxy-Hb] may be useful for monitoring fatigue in radiologists during image interpretation.

DOI： 10.1007/s11604-019-00826-2

【人工知能が医療を変える!医療分野におけるAI研究開発最前線2019】領域別・画像診断におけるAI研究開発の最前線胸部領域胸部画像診断におけるAIと臨床研究について

食道平滑筋腫 Reviewed

兵藤良太、岩野信吾、長縄慎二

画像診断 Vol. 39 ( 7 ) page： 662 - 663 2019.6

伊藤倫太郎, 岩野信吾, 長縄慎二

INNERVISION Vol. 34 ( 7 ) page： 25 - 28 2019.6

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：(株)インナービジョン

2006年から始まった第三次AIブームによりAIの研究が加速度的に進み、現在ではスマートフォンのカメラや音声入力など身近なものに活用されている。放射線医学においては古くから人工知能(AI)を用いた研究が行われ、臨床にも応用されていた。最近では、さらに発展したAIを用いたCADの開発が盛んであり、世界中の研究者が開発を競っている。本稿では、加速度的に進歩するAIと放射線医学とのかかわりについて、主に胸部画像診断の観点から現在の状況と問題点についてまとめ、実際の研究例について提示する。(著者抄録)

Increased signal intensity of low-concentration gadolinium contrast agent by longer repetition time in heavily T2-weighted-3D-FLAIR.

Kato Y, Bokura K, Taoka T, Naganawa S

Japanese journal of radiology Vol. 37 ( 5 ) page： 431-435 2019.5

Phase II study of chemoradiotherapy combined with gemcitabine plus nab-paclitaxel for unresectable locally advanced pancreatic ductal adenocarcinoma (NUPAT 05 Trial): study protocol for a single arm phase II study. Reviewed

Nao Takano, Suguru Yamada, Akihiro Hirakawa, Yukihiro Yokoyama, Hiroki Kawashima, Osamu Maeda, Tohru Okada, Eizaburo Ohno, Junpei Yamaguchi, Takuya Ishikawa, Fuminori Sonohara, Masaya Suenaga, Hideki Takami, Masamichi Hayashi, Yukiko Niwa, Yoshiki Hirooka, Yoshiyuki Ito, Shinji Naganawa, Yuichi Ando, Masato Nagino, Hidemi Goto, Tsutomu Fujii, Yasuhiro Kodera

Nagoya journal of medical science Vol. 81 ( 2 ) page： 233 - 239 2019.5

Language：English Publishing type：Research paper (scientific journal)

The efficacy of nab-paclitaxel combined with gemcitabine (GnP) and of chemoradiotherapy (CRT) for unresectable locally advanced pancreatic ductal adenocarcinoma (UR-LA PDAC) is still unclear. We previously conducted a phase I study of CRT using GnP and determined the recommended dose and have now designed a phase II trial to evaluate the efficacy of CRT incorporating GnP for UR-LA PDAC. Eligibility criteria are chemotherapy-naïve patients with UR-LA PDAC as defined by the NCCN guidelines version 2. 2016. Study patients will receive 100 mg/m2 nab-paclitaxel and 800 mg/m2 gemcitabine on Days 1, 8, and 15 per 4-week cycle with concurrent radiation therapy (total dose of 50.4 Gy in 28 fractions of 1.8 Gy per day, 5 days per week). Treatment will be continued until disease progression or surgery, which is to be performed only for patients in whom the disease is well-controlled at 8 months from beginning the protocol treatment. Primary endpoint is 2-year overall survival rate and co-primary endpoint is resection rate. Secondary endpoints are overall survival, progression free survival, time to treatment failure, response rate, disease control rate, early tumor shrinkage, depth of response, reduction of SUV-max on PET-CT, serum tumor markers, relative dose intensity, safety, and Quality of life. This study will show the efficacy and safety of chemoradiotherapy combined with GnP.

DOI： 10.18999/nagjms.81.2.233

子宮平滑筋肉腫 Reviewed

櫻井悠介、岩野信吾、長縄慎二、下山芳江、新美　薫

画像診断 Vol. 39 ( 6 ) page： 512 - 513 2019.5

画像診断と病理食道平滑筋腫

兵藤良太, 岩野信吾, 長縄慎二, 宮田一志, 島田聡子

画像診断 Vol. 39 ( 7 ) page： 662 - 663 2019.5

Utility of Metabolic Parameters on FDG PET/CT in the Classification of Early-Stage Lung Adenocarcinoma: Prediction of Pathological Invasive Size.

Iwano S, Ito S, Kamiya S, Ito R, Kato K, Naganawa S

Clinical nuclear medicine 2019.4

A case of human pancreatic eurytremiasis. Reviewed International journal

Hiroshi Ogawa, Yasuo Takehara, Shinji Naganawa, Junpei Yamaguchi, Masato Nakaguro

Abdominal radiology (New York) Vol. 44 ( 4 ) page： 1213 - 1216 2019.4

Language：English Publishing type：Research paper (scientific journal)

This study provides the first comprehensive imaging report of human pancreatic eurytremiasis. A 43-year-old man with obstructive jaundice and a pancreatic tumor was referred for diagnosis and treatment. Serum aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transpeptidase were elevated. Computed tomography (CT) revealed a multilocular cystic lesion with delayed enhanced area in the pancreas head. On magnetic resonance imaging, the tumor was hyperintense on diffusion-weighted image, and the apparent diffusion coefficient value of the tumor was lower than that of the normal pancreatic parenchyma. Positron emission tomography with 2-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed tomography (18F-FDG PET/CT) revealed abnormally increased uptake of 18F-FDG in the tumor. A subtotal stomach-preserving pancreaticoduodenectomy was performed on the preoperative diagnosis of pancreatic carcinoma accompanied by branch duct-type intraductal papillary mucinous neoplasm. Multifocal granulomatous lesions with necrotic areas including many parasite eggs were seen on the histology. The final diagnosis was pancreatic eurytremiasis.

DOI： 10.1007/s00261-019-01925-4

Quantitative Follow-Up Assessment of Patients with Interstitial Lung Disease by 3D-Curved High-Resolution CT Imaging Parallel to the Chest Wall. Reviewed

Clinical Features of Ears With Otosclerosis and Endolymphatic Hydrops.

Wang F, Yoshida T, Sugimoto S, Shimono M, Teranishi M, Naganawa S, Sone M

Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology Vol. 40 ( 4 ) page： 441-445 2019.4

Influence of implanted metals in new CT reconstruction algorithm for radiotherapy treatment planning

Kamomae T, Nakaya T, Kawabata F, Okudaira K, Kumagai M, Oguchi H, Itoh Y, Naganawa S

RADIOTHERAPY AND ONCOLOGY Vol. 133 page： S1132-S1132 2019.4

縦隔奇形腫 Reviewed

中根俊樹、岩野信吾、長縄慎二

画像診断 Vol. 39 ( 5 ) page： 380 - 381 2019.4

FDG-PET/CTの腫瘍代謝容積に基づいた肺腺癌の臨床病期診断の試み

岩野信吾, 伊藤倫太郎, 長縄慎二

肺癌 Vol. 59 ( 2 ) page： 189 - 189 2019.4

7テスラMR装置における高空間分解能3次元位相コントラスト磁気共鳴法を利用した脳血流動態解析の制度検証 Reviewed

田嶋駿亮、礒田治夫、福永雅喜、長縄慎二

脳とこころの研究センター脳疾患克服に向けた次世代創薬開発のためのコホート・コンソーシアム型研究拠点形成平成30年度活動報告書 Vol. - ( - ) page： 24 - 24 2019.3

腎静脈に発生した平滑筋肉腫 Invited Reviewed

松島正哉、林　葉子、岩野信吾、長縄慎二、下山芳江

画像診断 Vol. 39 ( 3 ) page： 252 - 253 2019.3

脳とこころの研究センター長　挨拶 Reviewed

長縄慎二

脳とこころの研究センター脳疾患克服に向けた次世代創薬開発のためのコホート・コンソーシアム型研究拠点形成平成30年度活動報告書 Vol. - ( - ) page： 1 - 1 2019.3

MRによる血液-脳間質液-脳脊髄液の動態の解明 Reviewed

長縄慎二、田岡俊昭、川井　恒

脳とこころの研究センター脳疾患克服に向けた次世代創薬開発のためのコホート・コンソーシアム型研究拠点形成平成30年度活動報告書 Vol. - ( - ) page： 29 - 30 2019.3

Hiroyasu Umakoshi, Shingo Iwano, Tsutomu Inoue, Yuanzhong Li, Keigo Nakamura, Shinji Naganawa

Nagoya journal of medical science Vol. 81 ( 1 ) page： 41 - 53 2019.2

Language：English Publishing type：Research paper (scientific journal)

We evaluated the progression of interstitial lung disease (ILD) by three-dimensional curved high-resolution computed tomography (3D-cHRCT) at a constant depth from the chest wall and compare the results to pulmonary function test (PFT) results on a follow-up assessment. We reviewed the patients with ILD who underwent HRCT and concurrent PFTs at least twice from April 2008 to December 2014. Forty-five patients with ILD were enrolled. 3D-cHRCT images of the lung at various depths from the chest wall were reconstructed, and total area (TA), high-attenuation area (HAA) >-500 HU, and %HAA ([HAA/TA] × 100) were calculated. The TA, HAA, and %HAA ratios (follow-up to baseline) were assessed for use in the diagnosis of physiologically progressive ILD (defined as; forced vital capacity [FVC] ratio <0.9 or %diffusing capacity of the lung for carbon monoxide [%DLCO] ratio <0.85 [follow-up to baseline]). Of all ratios obtained from 3D-cHRCT images at 5-30mm depths, the %HAA ratio at 20-mm had the largest area under the receiver operating characteristic curve (0.815, 95 % confidence interval 0.677-0.953). By univariate logistic regression analysis, TA, HAA, and %HAA ratios at 20-mm showed significant correlations with physiologically progressive ILD. 3D-cHRCT imaging performed in parallel with the chest wall offers novel quantitative parameters that are useful for following ILD.

DOI： 10.18999/nagjms.81.1.41

パーキンソン病におけるdefault mode network Reviewed

渡辺宏久、勝野雅央、長縄慎二、祖父江元

CLINICAL NEUROSCIENCE (月間　臨床神経科学) Vol. 37 ( 2 ) page： 212 - 216 2019.2

膵上皮内腫瘍性病変 Reviewed

小川　浩、岩野信吾、長縄慎二、中黒匡人

画像診断 Vol. 39 ( 2 ) page： 142 - 143 2019.2

原発性肺癌の術前臨床病期診断の正確性

岩野信吾, 馬越弘泰, 伊藤倫太郎, 島本宏矩, 長縄慎二

Japanese Journal of Radiology Vol. 37 ( Suppl. ) page： 25 - 25 2019.2

イピリムマブに伴う下垂体炎の3例

加藤理恵子, 川井恒, 田岡俊昭, 長縄慎二, 岩間信太郎

Japanese Journal of Radiology Vol. 37 ( Suppl. ) page： 25 - 25 2019.2

Significance of internal auditory canal diverticula in ears with otosclerosis.

Wang F, Yoshida T, Shimono M, Sugimoto S, Teranishi M, Naganawa S, Sone M

Acta oto-laryngologica page： 1-4 2019.1

画像診断と病理骨芽細胞腫

駒田智大, 岩野信吾, 長縄慎二, 新井英介, 西田佳弘, 下山芳江

画像診断 Vol. 39 ( 1 ) page： 4-5 - 5 2018.12

Signal Intensity of the Cerebrospinal Fluid after Intravenous Administration of Gadolinium-based Contrast Agents: Strong Contrast Enhancement around the Vein of Labbe.

Ohashi T, Naganawa S, Ogawa E, Katagiri T, Kuno K

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 2018.11

Can low b value diffusion weighted imaging evaluate the character of cerebrospinal fluid dynamics?

Taoka T, Naganawa S, Kawai H, Nakane T, Murata K

Japanese journal of radiology 2018.11

Age Dependence of Gadolinium Leakage from the Cortical Veins into the Cerebrospinal Fluid Assessed with Whole Brain 3D-real Inversion Recovery MR Imaging.

Naganawa S, Nakane T, Kawai H, Taoka T

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 2018.11

Analysis of late adverse events and their chronological changes after radiation therapy for cervical cancer

Yamada Takehiro, Ishihara Shunichi, Kawai Michiyasu, Itoh Yoshiyuki, Naganawa Shinji, Ikeda Mitsuru

NAGOYA JOURNAL OF MEDICAL SCIENCE Vol. 80 ( 4 ) page： 487-496 2018.11

2019年　最新医療機器の動向を探る　CTおよびMRIなどの画像診断機器の最新潮流ならびに今後のあり方

長縄慎二

医療機器システム白書 page： 14-17 2018.11

画像診断レポート未読問題について Reviewed

長縄慎二

健康文化 Vol. 53 ( - ) page： 138 - 142 2018.11

第三次人工知能ブーム？ Reviewed

長縄慎二

健康文化 Vol. 53 ( - ) page： 1 - 2 2018.11

Significance of Endolymphatic Hydrops Herniation Into the Semicircular Canals Detected on MRI.

Sugimoto S, Yoshida T, Teranishi M, Kobayashi M, Shimono M, Naganawa S, Sone M

Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology Vol. 39 ( 10 ) page： 1229-1234 2018.10

Involvement of the Precuneus/Posterior Cingulate Cortex Is Significant for the Development of Alzheimer's Disease: A PET (THK5351, PiB) and Resting fMRI Study. Reviewed International journal

Takamasa Yokoi, Hirohisa Watanabe, Hiroshi Yamaguchi, Epifanio Bagarinao, Michihito Masuda, Kazunori Imai, Aya Ogura, Reiko Ohdake, Kazuya Kawabata, Kazuhiro Hara, Yuichi Riku, Shinsuke Ishigaki, Masahisa Katsuno, Shinichi Miyao, Katsuhiko Kato, Shinji Naganawa, Ryuichi Harada, Nobuyuki Okamura, Kazuhiko Yanai, Mari Yoshida, Gen Sobue

Frontiers in aging neuroscience Vol. 10 page： 304 - 304 2018.10

Language：English Publishing type：Research paper (scientific journal)

Background: Imaging studies in Alzheimer's disease (AD) have yet to answer the underlying questions concerning the relationship among tau retention, neuroinflammation, network disruption and cognitive decline. We compared the spatial retention patterns of 18F-THK5351 and resting state network (RSN) disruption in patients with early AD and healthy controls. Methods: We enrolled 23 11C-Pittsburgh compound B (PiB)-positive patients with early AD and 24 11C-PiB-negative participants as healthy controls. All participants underwent resting state functional MRI and 18F-THK5351 PET scans. We used scaled subprofile modeling/principal component analysis (SSM/PCA) to reduce the complexity of multivariate data and to identify patterns that exhibited the largest statistical effects (variances) in THK5351 concentration in AD and healthy controls. Findings: SSM/PCA identified a significant spatial THK5351 pattern composed by mainly three clusters including precuneus/posterior cingulate cortex (PCC), right and left dorsolateral prefrontal cortex (DLPFC) which accounted for 23.6% of the total subject voxel variance of the data and had 82.6% sensitivity and 79.1% specificity in discriminating AD from healthy controls. There was a significant relationship between the intensity of the 18F-THK5351 covariation pattern and cognitive scores in AD. The spatial patterns of 18F-THK5351 uptake showed significant similarity with intrinsic functional connectivity, especially in the PCC network. Seed-based connectivity analysis from the PCC showed significant decrease in connectivity over widespread brain regions in AD patients. An evaluation of an autopsied AD patient with Braak V showed that 18F-THK5351 retention corresponded to tau deposition, monoamine oxidase-B (MAO-B) and astrogliosis in the precuneus/PCC. Interpretation: We identified an AD-specific spatial pattern of 18F-THK5351 retention in the precuneus/PCC, an important connectivity hub region in the brain. Disruption of the functional connections of this important network hub may play an important role in developing dementia in AD.

DOI： 10.3389/fnagi.2018.00304

Diagnostic Radiology Service in Japan. Reviewed Open Access

Shinji Naganawa, Yukunori Korogi

Japanese journal of radiology Vol. 36 ( 10 ) page： 575 - 578 2018.10

Impact of the Glymphatic System on the Kinetic and Distribution of Gadodiamide in the Rat Brain: Observations by Dynamic MRI and Effect of Circadian Rhythm on Tissue Gadolinium Concentrations. Reviewed International journal Open Access

Toshiaki Taoka, Gregor Jost, Thomas Frenzel, Shinji Naganawa, Hubertus Pietsch

Investigative radiology Vol. 53 ( 9 ) page： 529 - 534 2018.9

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVES: The glymphatic system is a recently hypothesized waste clearance system of the brain in which perivascular space constitutes a pathway similar to the lymphatic system in other body regions. Sleep and anesthesia are reported to influence the activity of the glymphatic system. Because rats are nocturnal animals, the glymphatic system is expected to be more active during the day. We attempted to elucidate the influence of the glymphatic system for intravenously injected gadodiamide in the rat brain by 2 experiments. One was a magnetic resonance imaging (MRI) experiment to evaluate the short-term dynamics of signal intensity changes after gadodiamide administration. The other was a quantification experiment to evaluate the concentration of retained gadolinium within the rat brain after repeated intravenous administration of gadodiamide at different times of day and levels of anesthesia. MATERIALS AND METHODS: The imaging experiment was performed on 6 rats that received an intravenous injection of gadodiamide (1 mmol/kg) and dynamic MRI for 3 hours at 2.4-minute intervals. The time course of the signal intensity changes was evaluated for different brain structures. The tissue quantification experiment was performed on 24 rats divided into 4 groups by injection time (morning, late afternoon) and anesthesia (none, short, long) during administration. All animals received gadodiamide (1.8 mmol/kg, 8 times over 2 weeks). Gadolinium concentration of dissected brain tissues was quantified 5 weeks after the last administration by inductively coupled plasma mass spectrometry. RESULTS: In the imaging experiment, muscle and the fourth ventricle showed an instantaneous signal intensity increase immediately after gadodiamide injection. The signal curve of the cerebral cortex and deep cerebellar nuclei reached the peak signal intensity later than the fourth ventricle but earlier than that of the prepontine cistern. In the gadolinium quantification experiment, the concentration in the group with the morning injection showed a significantly lower concentration than the late afternoon injection group. The lowest tissue gadolinium concentrations were found in the groups injected in the morning during long anesthesia. CONCLUSIONS: Instantaneous transition of gadodiamide from blood to cerebrospinal fluid was indicated by dynamic MRI. The gadodiamide distribution to the cerebral cortex and deep cerebellar nuclei seemed to depend on both blood flow and cerebrospinal fluid. This confirms previous studies indicating that the cerebrospinal fluid is one potential pathway of gadolinium-based contrast agent entry into the brain. For the distribution and clearance of the gadodiamide from brain tissue, involvement of the glymphatic system seemed to be indicated in terms of the influence of sleep and anesthesia.

DOI： 10.1097/RLI.0000000000000473

Corpus callosal involvement is correlated with cognitive impairment in multiple system atrophy. Reviewed International journal

Kazuhiro Hara, Hirohisa Watanabe, Epifanio Bagarinao, Kazuya Kawabata, Noritaka Yoneyama, Reiko Ohdake, Kazunori Imai, Michihito Masuda, Takamasa Yokoi, Aya Ogura, Takashi Tsuboi, Mizuki Ito, Naoki Atsuta, Hisayoshi Niwa, Toshiaki Taoka, Satoshi Maesawa, Shinji Naganawa, Masahisa Katsuno, Gen Sobue

Journal of neurology Vol. 265 ( 9 ) page： 2079 - 2087 2018.9

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: We examined the anatomical involvement related to cognitive impairment in patients with multiple system atrophy (MSA). METHODS: We examined 30 patients with probable MSA and 15 healthy controls. All MSA patients were assessed by the Unified MSA-Rating scale and Addenbrooke's Cognitive Examination-Revised (ACE-R). We classified 15 MSA patients with ACE-R scores > 88 as having normal cognition (MSA-NC) and 15 with scores ≤ 88 as having cognitive impairment (MSA-CI). All subjects underwent 3 T MRI scanning and were investigated using voxel-based morphometry and diffusion tensor imaging. RESULTS: Both the MSA-NC and MSA-CI patients exhibited cerebellar but not cerebral atrophy in voxel-based morphometry compared to controls. In contrast, tract-based spatial statistics revealed widespread and significantly decreased fractional anisotropy (FA) values, as well as increased mean diffusivity, radial diffusivity, and axial diffusivity in both the cerebrum and cerebellum in MSA-CI patients compared to controls. MSA-NC patients also exhibited similar involvement of the cerebellum but less extensive involvement of the cerebrum compared with the MSA-CI patients. In particular, FA values in MSA-CI patients were significantly decreased in the anterior part of the left corpus callosum compared with those in MSA-NC patients. The mean FA values in the left anterior part of the corpus callosum were significantly correlated with total ACE-R scores and subscores (memory, fluency, and language) in MSA patients. CONCLUSIONS: Decreased FA values in the anterior corpus callosum showed a significant correlation with cognitive impairment in MSA.

DOI： 10.1007/s00415-018-8923-7

Generative Adversarial Networkを用いた肺結節の画像生成について

伊藤倫太郎, 岩野信吾, 長縄慎二

日本医学放射線学会秋季臨床大会抄録集 Vol. 54回 page： S561 - S561 2018.9

Histogram analysis of quantitative pharmacokinetic parameters on DCE-MRI: correlations with prognostic factors and molecular subtypes in breast cancer.

Nagasaka K, Satake H, Ishigaki S, Kawai H, Naganawa S

Breast cancer (Tokyo, Japan) 2018.8

【膵癌update】　診断　MRI/MRCP

小川　浩、竹原康雄、長縄慎二

臨床消化器内科 Vol. 33 ( 7 ) page： 789-793 2018.7

Inter-individual Comparison of Gadobutrol and Gadoteridol Tissue Time-intensity Profiles for Dynamic Susceptibility Contrast Perfusion MR Imaging.

Yamada M, Taoka T, Kawaguchi A, Yasuda K, Niinomi Y, Ohashi Y, Okuda T, Naganawa S

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 2018.5

Phase I study of chemoradiotherapy using gemcitabine plus nab-paclitaxel for unresectable locally advanced pancreatic cancer. Reviewed International journal

Suguru Yamada, Tsutomu Fujii, Yukihiro Yokoyama, Hiroki Kawashima, Osamu Maeda, Kojiro Suzuki, Tohru Okada, Eizaburo Ono, Junpei Yamaguchi, Nao Takano, Hideki Takami, Masamichi Hayashi, Yukiko Niwa, Yoshiki Hirooka, Yoshiyuki Ito, Shinji Naganawa, Yuichi Ando, Masato Nagino, Hidemi Goto, Yasuhiro Kodera

Cancer chemotherapy and pharmacology Vol. 81 ( 5 ) page： 815 - 821 2018.5

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: For unresectable locally advanced (UR-LA) pancreatic cancer, chemoradiotherapy has been recommended by the NCCN guidelines. We designed a chemoradiotherapy protocol using nab-paclitaxel combined with gemcitabine (GnP) for patients with UR-LA pancreatic cancer. The purpose of this phase I study was to determine a recommended dose (RD) for this novel regimen. METHODS: Patients with UR-LA pancreatic cancer were eligible. The frequency of dose-limiting toxicities (DLTs) was evaluated, and the RD was determined. Patients were classified according to the designated dose levels of chemoradiotherapy using the GnP regimen. After additional 6 cycles of the GnP regimen were administered, surgery was considered if the patients had stable disease and tumor marker levels had normalized. RESULTS: DLT (grade 4 thrombocytopenia) was observed only in 1 of 12 patients, and the RD was set at level 3. Grade 3-4 leukopenia was observed in 9 (75.0%) patients, and neutropenia in 7 (58.3%). The response rate was 41.7%, and the disease control rate was 100%. Conversion surgery was performed in 6 (50%) patients, and curative resection (R0) was performed in all 6 patients (100%). Stratification according to the Evans classification system demonstrated one patient with grade 1b, one with grade 2, two with grade 3, and two with grade 4 disease. CONCLUSION: The RD for weekly administration was 800 mg/m2 for gemcitabine and 100 mg/m2 for nab-paclitaxel with a 50.4 Gy radiation. The GnP regimen at this dosage was promising with 6 of 12 patients proceeding to conversion surgery, and should be evaluated further in a phase II trial.

DOI： 10.1007/s00280-018-3554-3

Diagnostic performance of 18F-FDG PET/CT and whole-body diffusion-weighted imaging with background body suppression (DWIBS) in detection of lymph node and bone metastases from pediatric neuroblastoma.

Ishiguchi H, Ito S, Kato K, Sakurai Y, Kawai H, Fujita N, Abe S, Narita A, Nishio N, Muramatsu H, Takahashi Y, Naganawa S

Annals of nuclear medicine 2018.4

An unbiased data-driven age-related structural brain parcellation for the identification of intrinsic brain volume changes over the adult lifespan.

Bagarinao E, Watanabe H, Maesawa S, Mori D, Hara K, Kawabata K, Yoneyama N, Ohdake R, Imai K, Masuda M, Yokoi T, Ogura A, Wakabayashi T, Kuzuya M, Ozaki N, Hoshiyama M, Isoda H, Naganawa S, Sobue G

NeuroImage Vol. 169 page： 134 - 144 2018.4

Tau Kinetics in Neurons and the Human Central Nervous System

Sato Chihiro, Barthelemy Nicolas R., Mawuenyega Kwasi G., Patterson Bruce W., Gordon Brian A., Jockel-Balsarotti Jennifer, Sullivan Melissa, Crisp Matthew J., Kasten Tom, Kirmess Kristopher M., Kanaan Nicholas M., Yarasheski Kevin E., Baker-Nigh Alaina, Benzinger Tammie L. S., Miller Timothy M., Karch Celeste M., Bateman Randall J.

NEURON Vol. 97 ( 6 ) page： 1284 - + 2018.3

Computer-aided Volumetry of Part-Solid Lung Cancers by Using CT: Solid Component Size Predicts Prognosis.

Kamiya S, Iwano S, Umakoshi H, Ito R, Shimamoto H, Nakamura S, Naganawa S

Radiology page： 172319 2018.3

Improved 3D-real Inversion Recovery: A Robust Imaging Technique for Endolymphatic Hydrops after Intravenous Administration of Gadolinium.

Naganawa S, Kawai H, Taoka T, Sone M

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 2018.3

Distinct manifestation of cognitive deficits associate with different resting-state network disruptions in non-demented patients with Parkinson's disease.

Kawabata K, Watanabe H, Hara K, Bagarinao E, Yoneyama N, Ogura A, Imai K, Masuda M, Yokoi T, Ohdake R, Tanaka Y, Tsuboi T, Nakamura T, Hirayama M, Ito M, Atsuta N, Maesawa S, Naganawa S, Katsuno M, Sobue G

Journal of neurology Vol. 265 ( 3 ) page： 688-700 2018.3

Distinct manifestation of cognitive deficits associate with different resting-state network disruptions in non-demented patients with Parkinson's disease

Kawabata Kazuya, Watanabe Hirohisa, Hara Kazuhiro, Bagarinao Epifanio, Yoneyama Noritaka, Ogura Aya, Imai Kazunori, Masuda Michihito, Yokoi Takamasa, Ohdake Reiko, Tanaka Yasuhiro, Tsuboi Takashi, Nakamura Tomohiko, Hirayama Masaaki, Ito Mizuki, Atsuta Naoki, Maesawa Satoshi, Naganawa Shinji, Katsuno Masahisa, Sobue Gen

JOURNAL OF NEUROLOGY Vol. 265 ( 3 ) page： 688-700 2018.3

特集　脳脊髄液動態のすべて　脳脊髄液による老廃物のクリアランス―glymphaticシステム―

田岡俊昭、長縄慎二

画像診断 Vol. 38 ( 3 ) page： 268-276 2018.3

後下小脳動脈抹消部動脈瘤の診断におけるthin slab MIP法の有用性

長縄慎二

日本脳神経CI学会機関誌 Vol. 39 ( 3-4 ) page： 121-130 2018.3

MR画像による脳内の物質輸送機構の解明

長縄慎二、田岡俊昭、川井　恒

脳とこころの研究センター　脳疾患克服に向けた次世代創薬開発のためのコホート・コンソーシアム型研究拠点形成　　　平成29年度活動報告書 page： 25-26 2018.3

脳とこころの研究センター長　挨拶

長縄慎二

脳とこころの研究センター　脳疾患克服に向けた次世代創薬開発のためのコホート・コンソーシアム型研究拠点形成　　　平成29年度活動報告書 page： 1 2018.3

Patients with anti-thyroid antibodies are prone to develop destructive thyroiditis by nivolumab: a prospective study Reviewed

Tomoko Kobayashi, Shintaro Iwama, Yoshinori Yasuda, Norio Okada, Taku Tsunekawa, Takeshi Onoue, Hiroshi Takagi, Daisuke Hagiwara, Yoshihiro Ito, Yoshiaki Morishita, Motomitsu Goto, Hidetaka Suga, Ryoichi Banno, Kenji Yokota, Tetsunari Hase, Masahiro Morise, Naozumi Hashimoto, Masahiko Ando, Hitoshi Kiyoi, Momokazu Gotoh, Yuichi Ando, Masashi Akiyama, Yoshinori Hasegawa, Hiroshi Arima

Journal of the Endocrine Society 2018.2

Detecting sub-second changes in brain activation patterns during interictal epileptic spike using simultaneous EEG-fMRI. Reviewed International journal Open Access

Epifanio Bagarinao, Satoshi Maesawa, Yuji Ito, Naotaka Usui, Jun Natsume, Hirohisa Watanabe, Minoru Hoshiyama, Toshihiko Wakabayashi, Gen Sobue, Shinji Naganawa, Haruo Isoda

Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology Vol. 129 ( 2 ) page： 377 - 389 2018.2

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: Epileptic spikes are associated with rapidly changing brain activation involving the epileptic foci and other brain regions in the "epileptic network". We aim to resolve these activation changes using simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) recordings. METHODS: Simultaneous EEG-fMRI recordings from 9 patients with epilepsy were used in the analysis. Our method employed the whole scalp EEG data to generate regressors for the analysis of fMRI data using the general linear model. RESULTS: We were able to resolve, with milliseconds temporal resolution, changes in activation patterns involving suspected epileptic foci and other brain regions in the epileptic network during spike and slow wave. Using summary maps (called SSWAS maps) which show the activation frequency of voxels, we found that suspected epileptic foci tend to be significantly active during this interval. SSWAS maps also enabled the detection of the epileptic foci in 4 of 5 patients where the conventional event-timing-based analysis failed to identify. CONCLUSION: These findings demonstrated the efficacy of the method and the potential application of SSWAS maps to identify epileptic foci. SIGNIFICANCE: The method could help resolve activation changes during epileptic spike and could provide insights into the underlying pathophysiology of these changes.

DOI： 10.1016/j.clinph.2017.11.018

Imaging of the endolymphatic space in patients with Ménière's disease. Reviewed International journal

Tadao Yoshida, Satofumi Sugimoto, Masaaki Teranishi, Hironao Otake, Masahiro Yamazaki, Shinji Naganawa, Tsutomu Nakashima, Michihiko Sone

Auris, nasus, larynx Vol. 45 ( 1 ) page： 33 - 38 2018.2

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: To examine endolymphatic hydrops (EH) using magnetic resonance imaging (MRI) in patients with definite Ménière's disease (MD) and those with nonotological diseases. METHODS: We studied 32 patients with unilateral MD, 10 patients with bilateral MD and 21 patients with control ears who had other benign diseases not associated with hearing or vestibular dysfunction. The mean age of the subjects was 54.0 years (range 27-74) in the MD group and 56.1 years (range 24-79) in the control group. Using MRI, the degree of EH was classified as none, mild and significant in the cochlea and vestibule separately. The ratio of the area of endolymphatic space to the vestibular fluid space was calculated for the vestibule. The duration of MD was defined as the months between the first attack of MD and the MRI study. RESULTS: EH was present in the cochlea of 45/52 affected ears of patients with MD (87%) and in 16/42 control ears (38%). Significant cochlear hydrops was present in 37/52 affected ears (71%) and in 4/42 control ears (10%). EH in the vestibule was present in 49/52 affected ears (94%) and in 3/42 control ears (7%). Significant vestibular hydrops was present in 40/52 affected ears (77%) and in none of the 42 control ears. There was no relationship between the degree of EH and its duration. Using a cut off value for the relative size of EH in the vestibule of 41.9%, the test had a sensitivity of 88.5% and a specificity of 100% to diagnose definite MD. CONCLUSION: Cochlear EH was occasionally observed in control ears on MRI, as in normal temporal bone specimens. The presence or absence and degree of vestibular EH were significantly different between ears with MD and control ears. EH in the vestibule might be a specific predictor of definite MD.

DOI： 10.1016/j.anl.2017.02.002

【脳脊髄液動態のすべて】脳脊髄液による老廃物のクリアランス glymphaticシステム

早期声門癌に対するS-1併用化学放射線療法の長期成績

高瀬裕樹, 伊藤善之, 木村香菜, 岡田徹, 久保田誠司, 川村麻里子, 中原理絵, 大家祐実, 香西由加, 長縄慎二, 藤本保志, 曾根三千彦

Japanese Journal of Radiology Vol. 36 ( Suppl. ) page： 22 - 22 2018.2

胸壁並行断面CTを用いた間質性肺炎の経時的評価

馬越弘泰, 岩野信吾, 伊藤倫太郎, 島本宏矩, 長縄慎二

Japanese Journal of Radiology Vol. 36 ( Suppl. ) page： 19 - 19 2018.2

非小細胞肺癌の局所浸潤性の予測に関する造影dual energy CTとFDG-PET/CTの比較

伊藤倫太郎, 岩野信吾, 島本宏矩, 馬越弘泰, 伊藤信嗣, 長縄慎二, 加藤克彦

Japanese Journal of Radiology Vol. 36 ( Suppl. ) page： 20 - 20 2018.2

田岡俊昭, 長縄慎二

画像診断 Vol. 38 ( 3 ) page： 268 - 276 2018.2

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：(株)Gakken

glymphaticシステムは頭蓋内の脳脊髄液,脳内の間質液を含む循環に関連した1つのコンセプトであり,脳実質内の老廃物を洗い出すシステムとして広く受け入れられるようになりつつある.その一方で,以前から提唱されている細小動脈壁の排出路を介したシステムとの関連も含めて,この仮説に関して不明な点も多く,現時点で多くの議論がある.(著者抄録)

Other Link： https://search.jamas.or.jp/default/link?pub_year=2018&ichushi_jid=J00235&link_issn=&doc_id=20180226160007&doc_link_id=10.15105%2FGZ.0000000353&url=https%3A%2F%2Fdoi.org%2F10.15105%2FGZ.0000000353&type=%E5%8C%BB%E6%9B%B8.jp_%E3%82%AA%E3%83%BC%E3%83%AB%E3%82%A2%E3%82%AF%E3%82%BB%E3%82%B9&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00024_2.gif

Relationship between Contrast Enhancement of the Perivascular Space in the Basal Ganglia and Endolymphatic Volume Ratio. Reviewed Open Access

Toshio Ohashi, Shinji Naganawa, Toshio Katagiri, Kayao Kuno

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 17 ( 1 ) page： 67 - 72 2018.1

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: We routinely obtain the endolymphatic hydrops (EH) image using heavily T2-weighted three dimensional-fluid attenuated inversion recovery (hT2w-3D-FLAIR) imaging at 4 hours after intravenous administration of a single-dose of gadolinium-based contrast media (IV-SD-GBCM). While repeating the examination, we speculated that the contrast enhancement of the perivascular space (PVS) in the basal ganglia might be related to the degree of EH. Therefore, the purpose of this study was to investigate the relationship between the endolymphatic volume ratio (%ELvolume) and the signal intensity of the PVS (SI-PVS). MATERIALS AND METHODS: In 20 patients with a suspicion of EH, a heavily T2-weighted 3D-turbo spin echo sequence for MR cisternography (MRC) and an hT2w-3D-FLAIR as a positive perilymph image (PPI) were obtained at 4 hours after IV-SD-GBCM. The %ELvolume of the cochlea and the vestibule were measured on the previously reported HYDROPS2-Mi2 image. The PVS in the basal ganglia was segmented on MRC using a region-growing method. The PVS regions were copied and pasted onto the PPI, and the SI-PVS was measured. The larger value of the right and the left ears was employed as the %ELvolume, and the weighted average of both sides was employed as the SI-PVS. The correlation between the %ELvolume and the SI-PVS was evaluated. RESULT: There was a strong negative linear correlation between the %ELvolume of the cochlea and the SI-PVS (r = -0.743, P < 0.001); however, there was no significant correlation between the %ELvolume of the vestibule and the SI-PVS (r = -0.267, P = 0.256). CONCLUSION: There was a strong negative correlation between the cochlear %ELvolume and the SI-PVS. Contrast enhancement of PVS might be a biomarker of EH.

DOI： 10.2463/mrms.mp.2017-0001

Gadolinium-based Contrast Media, Cerebrospinal Fluid and the Glymphatic System: Possible Mechanisms for the Deposition of Gadolinium in the Brain. Reviewed

Toshiaki Taoka, Shinji Naganawa

Magn Reson Med Sci. 2018.1

Effects of Gradient Coil Noise and Gradient Coil Replacement on the Reproducibility of Resting State Networks. Reviewed International journal Open Access

Epifanio Bagarinao, Erina Tsuzuki, Yukina Yoshida, Yohei Ozawa, Maki Kuzuya, Takashi Otani, Shuji Koyama, Haruo Isoda, Hirohisa Watanabe, Satoshi Maesawa, Shinji Naganawa, Gen Sobue

Frontiers in human neuroscience Vol. 12 page： 148 - 148 2018

Language：English Publishing type：Research paper (scientific journal)

The stability of the MRI scanner throughout a given study is critical in minimizing hardware-induced variability in the acquired imaging data set. However, MRI scanners do malfunction at times, which could generate image artifacts and would require the replacement of a major component such as its gradient coil. In this article, we examined the effect of low intensity, randomly occurring hardware-related noise due to a faulty gradient coil on brain morphometric measures derived from T1-weighted images and resting state networks (RSNs) constructed from resting state functional MRI. We also introduced a method to detect and minimize the effect of the noise associated with a faulty gradient coil. Finally, we assessed the reproducibility of these morphometric measures and RSNs before and after gradient coil replacement. Our results showed that gradient coil noise, even at relatively low intensities, could introduce a large number of voxels exhibiting spurious significant connectivity changes in several RSNs. However, censoring the affected volumes during the analysis could minimize, if not completely eliminate, these spurious connectivity changes and could lead to reproducible RSNs even after gradient coil replacement.

DOI： 10.3389/fnhum.2018.00148

Differences in Signal Intensity and Enhancement on MR Images of the Perivascular Spaces in the Basal Ganglia versus Those in White Matter

Naganawa Shinji, Nakane Toshiki, Kawai Hisashi, Taoka Toshiaki

MAGNETIC RESONANCE IN MEDICAL SCIENCES Vol. 17 ( 4 ) page： 301-307 2018

Clinical MR imaging of endolymphatic hydrops: Updates on scanning methods, image processing and interpretation. Reviewed

Shinji Naganwa

Solutions in Contrast Imaging. Vol. 9 ( 5 ) page： 1-5 2018

Dosimetric feasibility of using tungsten-based functional paper for flexible chest wall protectors in intraoperative electron radiotherapy for breast cancer. Reviewed International journal Open Access

Takeshi Kamomae, Hajime Monzen, Mariko Kawamura, Kuniyasu Okudaira, Takayoshi Nakaya, Takashi Mukoyama, Yoshikazu Miyake, Yoshitomo Ishihara, Yoshiyuki Itoh, Shinji Naganawa

Physics in medicine and biology Vol. 63 ( 1 ) page： 015006 - 015006 2017.12

Language：English Publishing type：Research paper (scientific journal)

Intraoperative electron radiotherapy (IOERT), which is an accelerated partial breast irradiation method, has been used for early-stage breast cancer treatment. In IOERT, a protective disk is inserted behind the target volume to minimize the dose received by normal tissues. However, to use such a disk, the surgical incision must be larger than the field size because the disk is manufactured from stiff and unyielding materials. In this study, the applicability of newly developed tungsten-based functional paper (TFP) was assessed as an alternative to the existing protective disk. The radiation-shielding performance of the TFP was verified through experimental measurements and Monte Carlo simulations. Percentage depth dose curves and lateral dose profiles with and without TFPs were measured and simulated on a dedicated IOERT accelerator. The number of piled-up TFPs was changed from 1 to 40. In the experimental measurements, the relative doses at the exit plane of the TFPs for 9 MeV were 42.7%, 9.2%, 0.2%, and 0.1% with 10, 20, 30, and 40 TFPs, respectively, whereas those for 12 MeV were 63.6%, 27.1%, 8.6%, and 0.2% with 10, 20, 30, and 40 TFPs, respectively. Slight dose enhancements caused by backscatter radiation from the TFPs were observed at the entrance plane of the TFPs at both beam energies. The results of the Monte Carlo simulation indicated the same tendency as the experimental measurements. Based on the experimental and simulated results, the radiation-shielding performances of 30 TFPs for 9 MeV and 40 TFPs for 12 MeV were confirmed to be acceptable and close to those of the existing protective disk. The findings of this study suggest the feasibility of using TFPs as flexible chest wall protectors in IOERT for breast cancer treatment.

DOI： 10.1088/1361-6560/aa96cf

An unbiased data-driven age-related structural brain parcellation for the identification of intrinsic brain volume changes over the adult lifespan. Reviewed

Epifanio Bagarinao, Hirohisa Watanabe, Satoshi Maesawa, Daisuke Mori, Kazuhiro Hara, Kazuya Kawabata, Noritaka Yoneyama, Reiko Ohdake, Kazunori Imai, Michihito Masuda, Takamasa Yokoi, Aya Ogura, Toshihiko Wakabayashi, Masafumi Kuzuya, NorioOzaki, Minoru Hoshiyama, Haruo Isoda, Shinji Naganawa, Gen Sobue

Neuroimage ( 169 ) page： 134-144 2017.12

Longitudinal up-regulation of endolymphatic hydrops in patients with Meniere's disease during medical treatment. Reviewed International journal

Munehisa Fukushima, Tadashi Kitahara, Ryohei Oya, Shiro Akahani, Hidenori Inohara, Shinji Naganawa, Noriaki Takeda

Laryngoscope investigative otolaryngology Vol. 2 ( 6 ) page： 344 - 350 2017.12

Language：English Publishing type：Research paper (scientific journal)

Objective/Hypothesis: Meniere's disease (MD) is a common inner ear disease characterized by repeated episodic vertigo, fluctuating sensorineural hearing loss, and tinnitus. Its pathology is defined as endolymphatic hydrops (EH) in the inner ear and EH has been hypothesized to correlate with the clinical symptoms of MD. We presented the dynamics of in vivo EH in MD patients during medical treatments. Study Design: Prospective, single-arm repeated measures. Methods: Eleven MD patients were enrolled. All subjects prospectively underwent gadolinium-enhanced inner ear magnetic resonance (MR) imaging and neuro-otological testing before and after medical treatment. The volume of EH was quantitatively evaluated by processing MR images. All MD patients were administered continuous medication and followed up for more than 12 months. Results: The frequency of vertigo episodes decreased in all patients and vestibular function decreased to 13-91% of the pre-treatment level. The volume ratio of post-treatment EH-to-pre-treatment EH ranged from 1.01-3.22. The total volume of pre-treatment EH was significantly correlated with cochlear symptom disease duration and the affected ear's hearing level. Conclusion: EH in MD patients developed longitudinally with deterioration of inner ear function during medical treatment. The natural course of MD may progress with development of EH at least for a certain period. Level of Evidence: 2b.

DOI： 10.1002/lio2.115

【中枢神経系の新たな疾患カテゴリーとその画像所見】Glymphaticシステム脳内の老廃物排除のための仕組み

田岡俊昭, 長縄慎二

臨床画像 Vol. 33 ( 12 ) page： 1447 - 1458 2017.12

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：(株)メジカルビュー社

Glymphaticシステムは頭蓋内の脳脊髄液、脳内の間質液を含む循環に関連した1つのコンセプトであり、脳脊髄液の循環に関しての新しい考え方とともに広く受け入れられるようになりつつあり、さまざまな疾患と関連している可能性が指摘されている。(著者抄録)

Other Link： https://search.jamas.or.jp/default/link?pub_year=2017&ichushi_jid=J01843&link_issn=&doc_id=20171201080008&doc_link_id=%2Fap4ringc%2F2017%2F003312%2F009%2F1447-1458%26dl%3D0&url=https%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fap4ringc%2F2017%2F003312%2F009%2F1447-1458%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Clinical outcomes of 125I brachytherapy with and without external-beam radiation therapy for localized prostate cancer: results from 300 patients at a single institution in Japan. Reviewed International journal Open Access

Sayo Maki, Yoshiyuki Itoh, Seiji Kubota, Tohru Okada, Rie Nakahara, Junji Ito, Mariko Kawamura, Shinji Naganawa, Yasushi Yoshino, Takashi Fujita, Masashi Kato, Momokazu Gotoh, Mitsuru Ikeda

Journal of radiation research Vol. 58 ( 6 ) page： 870 - 880 2017.11

Language：English Publishing type：Research paper (scientific journal)

The aim of this study was to determine the outcomes and adverse events for 300 men with prostate cancer treated with 125iodine (125I) brachytherapy with and without external-beam radiation therapy (EBRT) at a single institution in Japan. Between February 2005 and November 2011, 300 consecutive patients with clinically localized prostate cancer were treated with 125I brachytherapy at the Nagoya University Hospital. A total of 271 men were treated with implants with doses of 145 Gy, and 29 men were treated with implants with doses of 110 Gy combined with EBRT (40-50 Gy/20-25 fractions). The median patient age was 69 years (range, 53-83 years). The median follow-up period was 53 months (range, 5-99 months). According to the National Comprehensive Cancer Network risk classification, 132 men (44%) had low-risk, 147 men (29%) had intermediate-risk and 21 men (7%) had high-risk disease. The 5-year overall survival rate, biochemical relapse-free survival rate, and disease-specific survival rates were 93.5%, 97.3% and 98.5%, respectively. Two men (0.6%) died of prostate cancer and 10 men (3.3%) died of other causes. Seventeen men (5.6%) experienced Grade 2 rectal bleeding in all: 12 (41.4%) of 29 in brachytherapy with EBRT, and 5 (1.8%) of 271 in brachytherapy alone. The rates of Grade 2 and 3 genitourinary toxicity were 1.0% and 1.7%, respectively. Excellent local control was achieved at our hospital for localized prostate cancer with 125I brachytherapy with and without EBRT. Gastrointestinal and genitourinary toxicities were acceptable.

DOI： 10.1093/jrr/rrx051

【局所進行膵癌の治療限界に挑む】局所進行膵癌の術前治療後の画像診断

The Relationship Between Endolymphatic Hydrops in the Vestibule and Low-Frequency Air-Bone Gaps. Reviewed

Satofumi Sugimoto, Tadao Yoshida, Masaaki Teranishi, Yuriko Okazaki, Shinji Naganawa, Michihiko Sone

The Laryngoscope. Vol. 28 ( 7 ) page： 1658 - 1662 2017.11

Letter to editor [Saccular measurements in routine MRI can predict hydrops in Meniele disease] by Simon F et al.

Pablo Dominguez, Shinji Naganawa

Eur Arch Otorhinolaryngol. 2017.11

小川浩, 鈴木耕次郎, 竹原康雄, 長縄慎二

胆と膵 Vol. 38 ( 11 ) page： 1255 - 1260 2017.11

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：医学図書出版(株)

膵癌は、血管浸潤の範囲と遠隔転移・腹膜播種の有無により、切除可能、切除境界、切除不能に分類される。このうち、局所進行膵癌である切除境界および切除不能膵癌に関しては、化学療法あるいは化学放射線療法により癌細胞が減少し、外科的切除が可能となる症例が存在する。膵癌の治療効果判定は、CTやMRI、PETといった画像や、CA19-9などの腫瘍マーカーの推移でみるのが一般的である。ここでは、とくに局所進行膵癌の術前治療後の画像診断について述べ、さらに化学放射線療法後に生じる多彩な画像上の変化についても言及する。(著者抄録)

The retention pattern of THK5351 pet imaging and functional network disruption associated with development of Alzheimer's disease

Yokoi T, Watanabe H, Yamaguchi H, Bagarinao E, Masuda M, Imai K, Ogura A, Ohdake R, Kawabata K, Hara K, Riku Y, Ishigaki S, Katsuno M, Kato K, Naganawa S, Okamura N, Miyao S, Yanai K, Sobue G

JOURNAL OF THE NEUROLOGICAL SCIENCES Vol. 381 page： 960 - 961 2017.10

Improved HYDROPS: Imaging of Endolymphatic Hydrops after Intravenous Administration of Gadolinium. Reviewed Open Access

Shinji Naganawa, Hisashi Kawai, Toshiaki Taoka, Michihiko Sone

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 16 ( 4 ) page： 357 - 361 2017.10

Language：English Publishing type：Research paper (scientific journal)

To improve the imaging protocol for the evaluation of endolymphatic hydrops after intravenous administration of a gadolinium-based contrast agent, we modified our previously reported hybrid of reversed image of positive endolymph signal and native image of positive perilymph signal (HYDROPS) method. Although the scan time of the new protocol was half that of the previous one, there were no significant differences between two protocols in the mean contrast noise ratio between the endolymph and perilymph and the area ratio of the endolymph size values in nine patients.

DOI： 10.2463/mrms.tn.2016-0126

Improved HYDROPS: Imaging of Endolymphatic Hydrops after Intravenous Administration of Gadolinium. Reviewed

Shinji Naganawa, Hisashi Kawai, Toshiaki Taoka, Michihiko Sone

Magn Reson Med Sci. ( 16 ) page： 357-361 2017.10

Longitudinal Up-Regulation of Endolymphatic Hydrops in Patients with Meniere's Disease During Medical Treatment. Reviewed

Munehisa Fukushima, Tadashi Kitahara, Ryohei Oya, Shiro Akahani, Hidenori Inohara, Shinji Naganawa, Noriaki Takeda

Laryngoscope Investigative Otolaryngology. Vol. - ( - ) 2017.10

Three-dimensional printer-generated patient-specific phantom for artificial in vivo dosimetry in radiotherapy quality assurance. Reviewed

Phys Med. 2017.10

A comparative analysis of dual-phase dual-energy CT and FDG-PET/CT for the prediction of histopathological invasiveness of non-small cell lung cancer. Reviewed International journal

Rintaro Ito, Shingo Iwano, Hironori Shimamoto, Hiroyasu Umakoshi, Koji Kawaguchi, Shinji Ito, Katsuhiko Kato, Shinji Naganawa

European journal of radiology Vol. 95 page： 186 - 191 2017.10

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: To compare dual-phase dual-energy CT (DE-CT) with FDG-PET/CT for predicting histopathological locoregional invasiveness of non-small cell lung cancers (NSCLCs). MATERIALS AND METHODS: We selected 63 consecutive patients with NSCLC lesions (37 males, 26 females; age range, 44-85 years; mean age, 69 years) who were evaluated preoperatively by both DE-CT and PET/CT at our institution. Postoperative microscopic invasiveness (lymphatic permeation, vascular invasion, and/or pleural involvement) was reviewed, and we defined locoregionally invasive tumors as those that had at least one positive finding of microscopic invasiveness. DE-CT scanning in the arterial and delayed phases was performed after injection of iodinated contrast media using 140-kVp and 80-kVp tube voltages. Three-dimensional iodine-related attenuation of primary tumors in the arterial and delayed phases was quantified automatically using "syngo Dual Energy Lung Nodules" application software, and the ratio of arterial phase to delayed phase enhancement (A/D ratio) was calculated. The A/D ratio and SUVmax on PET/CT were evaluated with respect to postoperative invasiveness by univariate logistic regression analysis. RESULTS: The A/D ratio was significantly correlated with lymphatic permeation, vascular invasion, and pleural involvement (p=0.011, p=0.021, and p=0.010, respectively). In contrast, the SUVmax was significantly correlated with pleural involvement (p=0.020) but not with lymphatic permeation or vascular invasion (p=0.088 and p=0.100, respectively). In the subgroup of patients with lesion diameters ≤2cm, the A/D ratio was significantly correlated with locoregional invasiveness (p=0.040), while the SUVmax was not (p=0.121). CONCLUSION: For the prediction of microscopic invasiveness of NSCLCs, the diagnostic performance of dual-phase DE-CT may be comparable to that of FDG-PET/CT.

DOI： 10.1016/j.ejrad.2017.08.010

ちょっと気になる胆・膵画像ティーチングファイルから(第36回) 主膵管内腫瘍栓を呈した腺房細胞癌の1例

小川浩, 竹原康雄, 館靖, 長縄慎二, 鈴木耕次郎, 廣岡芳樹, 山田豪, 藤井努, 下山芳江

胆と膵 Vol. 38 ( 10 ) page： 1131 - 1134 2017.10

Appearance of the Organum Vasculosum of the Lamina Terminalis on Contrast-enhanced MR Imaging.

Naganawa S, Taoka T, Kawai H, Yamazaki M, Suzuki K

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 2017.9

Clinical usefulness of MLCs in robotic radiosurgery systems for prostate SBRT. Reviewed

Masashi Tomida, Takeshi Kamomae, Junji Suzuki, Yoichi Ohashi, Yoshiyuki Itoh, Hiroshi Oguchi, Takahito Okuda

J Appl Clin Med Phys. Vol. 18 ( 5 ) page： 124-133 2017.9

Quantitative evaluation of interstitial pneumonia using 3D-curved high-resolution CT imaging parallel to the chest wall: A pilot study. Reviewed

Hiroyasu Umakoshi, Shingo Iwano, Tsutomu Inoue, Yuanzhong Li, Shinji Naganawa

PLoS One. Vol. 12 ( 9 ) page： e0185532. 2017.9

Significance of Endolymphatic Hydrops in Ears With Unilateral Sensorineural Hearing Loss. International journal

Yuriko Okazaki, Tadao Yoshida, Satofumi Sugimoto, Masaaki Teranishi, Ken Kato, Shinji Naganawa, Michihiko Sone

Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology Vol. 38 ( 8 ) page： 1076 - 1080 2017.9

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: The purpose of this study was to investigate the existence of endolymphatic hydrops (EH) in affected and unaffected ears in patients with unilateral sensorineural hearing loss (SNHL) using contrast-enhanced magnetic resonance imaging (MRI), and to evaluate the significance of EH in various otological diseases. STUDY DESIGN: Retrospective study. SETTING: University hospital. METHODS: One hundred eighty-two ears from 91 patients with unilateral SNHL were studied. The endolymphatic space was evaluated using 3-Tesla MRI with gadodiamide hydrate. Imaging data about the degree of EH in the cochlea and vestibule were analyzed and compared between ears with various otological diseases. RESULTS: All affected ears with delayed endolymphatic hydrops had EH. In affected ears with definite Menière's disease, cochlear EH was observed in all ears and vestibular EH in 93% of ears, and these rates were significantly higher in the affected than in the unaffected ears. EH was also observed in the cochlea and vestibule in 66% and 41%, respectively, of the affected ears with idiopathic sudden SNHL; however, these percentages did not differ significantly from those in the unaffected ears (52% and 38%, respectively). CONCLUSION: MRI showed that a high percentage of ears affected by Menière's disease or delayed endolymphatic hydrops had EH. Further studies should evaluate the implications of EH in ears, especially in those with sudden SNHL, in terms of secondary or pre-existing EH.

DOI： 10.1097/MAO.0000000000001499

Letter to Editors: Detection of endolymphatic hydrops using traditional MR imaging sequences

Shinji Naganawa, Michihiko Sone

American Journal of Otolaryngology - Head and Neck Medicine and Surgery Vol. 38 ( 5 ) page： 637 - 638 2017.9

A comparative analysis of dual-phase dual-energy CT and FDG-PET/CT for the prediction of histopathological invasiveness of non-small cell lung cancer. Reviewed

Rintaro Ito, Shingo Iwano, Hironori Shimamoto, Hiroyasu Umakoshi, Koji Kawaguchi, Shinji Ito, Katsuhiko Kato, Shinji Naganawa

European Journal of Radiology. ( 95 ) page： 186-191 2017.8

Optimized treatment strategy of radiotherapy for early glottic squamous cell carcinomas: An initial analysis. Reviewed

Nagoya J Med Sci. Vol. 79 ( 3 ) page： 331-338 2017.8

FDG-PET/CT predicts survival and lung metastasis of hypopharyngeal cancer in a multi-institutional retrospective study. Reviewed

Hidenori Suzuki, Katsuhiko Kato, Masami Nishio, Tsuneo Tamaki, Yasushi Fujimoto, Mariko Hiramatsu, Nobuhiro Hanai, Takeshi Kodaira, Yoshiyuki Itoh, Shinji Naganawa, Michihiko Sone, Yasuhisa Hasegawa

Annals of nuclear medicine Vol. 31 ( 7 ) page： 514 - 520 2017.8

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVES: We investigated a possible correlation between the maximum standardized uptake value (SUVmax), which is assessed by pretreatment 18F-fluorodeoxyglucose positron emission tomography with computed tomography, and the overall survival (OS) in patients with hypopharyngeal squamous cell carcinoma from two institutions on long-term follow-up, and examined whether SUVmax is correlated with several survival outcomes, including lung metastasis-free survival. METHODS: A total of 81 patients were enrolled. The survival rate was calculated by the Kaplan-Meier method. Both univariate and multivariate survival analyses were assessed by a Cox proportional hazards model. RESULTS: SUVmax ≥15.2 in institution A (p = 0.0306) or SUVmax ≥8 in institution B (p = 0.0132) was significantly predictor of a lower OS. We disaggregated the data by high SUVmax (SUVmax ≥15.2 from institution A and SUVmax ≥8 from institution B) and low SUVmax (SUVmax <15.2 from institution A and SUVmax <8 from institution B). Patients with a high SUVmax exhibited a significantly lower OS in both univariate (p = 0.001) and multivariate (p = 0.0046) analyses for adjusted for the clinical stage and treatment group. The patients with a high SUVmax exhibited significantly shorter disease-specific (p = 0.0068), distant metastasis-free (p = 0.0428), and lung metastasis-free (p = 0.0328) survivals. CONCLUSIONS: High SUVmax was significantly correlated with a lower OS, disease-specific survival, distant metastasis-free survival, and lung metastasis-free survival in a multi-institutional retrospective study.

DOI： 10.1007/s12149-017-1176-1

Optimized treatment strategy of radiotherapy for early glottic squamous cell carcinomas: An initial analysis. Reviewed

Nagoya journal of medical science Vol. 79 ( 3 ) page： 331 - 338 2017.8

Language：English Publishing type：Research paper (scientific journal)

The purpose of this study was to evaluate the clinical outcomes of radiotherapy for patients with T1/T2 glottic carcinoma. Patients with T1/T2 glottic carcinoma histopathologically diagnosed with squamous cell carcinoma and treated at our hospital between 2007 and 2015 were analyzed retrospectively. Our strategy for T1/T2 glottic carcinoma was as follows: radiotherapy alone with 2.25 Gy per fraction to a total of 25-28 fractions for patients with non-bulky T1 glottic carcinoma; concurrent chemoradiotherapy with oral S-1 and radiotherapy with 2 Gy per fraction to a total of 30 fractions for patients with T1 bulky/T2 favorable glottic carcinoma; or chemoradiotherapy with high-dose cisplatin and radiotherapy with 2 Gy per fraction to a total of 35 fractions for T2 unfavorable glottic carcinoma. Forty-eight patients were eligible. The median follow-up period among surviving patients was 38 months (range, 11-107). The disease was T1a in 23%, T1b in 13%, and T2 in 65% of patients. The 3-year local control rate in all patients, T1a, T1b, and T2 was 96.7%, 100%, 100%, and 96.0%, respectively. Of the 46 patients, one with T2 glottic carcinoma developed recurrent disease at the primary site, and one with T2 glottic carcinoma had lymph node recurrences in the neck. Acute Grade 3 dermatitis occurred in 8 (17%) patients and late Grade 2 hypothyroidism occurred in 2 (4%) patients. This retrospective study shows that our optimized treatment strategy of radiotherapy depending on the stage of early glottic carcinoma is not only effective but also well-tolerated.

DOI： 10.18999/nagjms.79.3.331

Development of the breast immobilization system in prone setup: The effect of bra in prone position to improve the breast setup error. Reviewed International journal Open Access

Mariko Kawamura, Yoshikazu Maeda, Kazutaka Yamamoto, Shigeyuki Takamatsu, Yoshitaka Sato, Hiroki Minami, Yusuke Saga, Kyo Kume, Yuji Tameshige, Makoto Sasaki, Hiroyasu Tamamura, Kouji Ohta, Yoshiyuki Itoh, Shinji Naganawa

Journal of applied clinical medical physics Vol. 18 ( 4 ) page： 155 - 160 2017.7

Language：English Publishing type：Research paper (scientific journal)

PURPOSE/OBJECTIVE(S): Accurate and reproducible positioning of the breast is difficult due to its deformability and softness; thus, targeting a breast tumor or tumor bed with fractionated radiotherapy using external beam radiation is difficult. The aim of this study was to develop a novel bra to aid in breast immobilization in the prone position. MATERIALS & METHODS: To assess the accuracy of prone position fixation of breast tumors, 33 breast cancer patients with 34 lesions were recruited. The bra used in this verification was customized from a commercially available bra. Duplicate MRI were acquired in the prone position, alternating with and without the bra, and for each series, patients were asked to step off the MRI table and re-set up in the prone position. Patients were also asked to remove and re-fit the bra for the second MRI. Each pair of images were superimposed to match the shape of the skin surface, and the maximum difference in tumor geometric center in three axes was measured. The required set up margin was calculated as: required margin = mean difference in geometric center + 2.5 standard deviation. The volumetric overlap of the tumor, as well as contouring uncertainties, was evaluated using contour analysis software. RESULTS: The median breast size was 498 cc. The required margins for the lateral, vertical, and longitudinal directions were estimated to be 4.1, 4.1, and 5.0 mm, respectively, with the bra, and 5.1, 6.9, and 6.7 mm, respectively, without the bra. These margins covered the dislocation of more than 33 lesions in total. With the bra, 33 lesions had achieved an objective overlap of 95% and 99% with 2 and 4 mm margins, respectively, whereas 4 and 8 mm, respectively, were needed without the bra. CONCLUSION: The use of an immobilizing bra reduced the setup margin for prone position fixation of breast tumors.

DOI： 10.1002/acm2.12116

Portal Vein Bleeding after Pancreatectomy: Diagnosis and Stent Graft Repair - A Consecutive Case Series

Suzuki Kojiro, Ebata Tomoki, Komada Tomohiro, Matsushima Masaya, Mizuno Takashi, Igami Tsuyoshi, Sugawara Gen, Yokoyama Yukihiro, Naganawa Shinji, Nagino Masato

JOURNAL OF THE PANCREAS Vol. 18 ( 4 ) page： 339 - 344 2017.7

Progression of mean pulmonary arterial pressure in idiopathic pulmonary fibrosis with mild to moderate restriction Reviewed

Ryo Teramachi, Hiroyuki Taniguchi, Yasuhiro Kondoh, Masahiko Ando, Tomoki Kimura, Kensuke Kataoka, Atsushi Suzuki, Taiki Furukawa, Koji Sakamoto, Yoshinori Hasegawa

RESPIROLOGY Vol. 22 ( 5 ) page： 986 - 990 2017.7

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY

Background and objectiveElevation of mean pulmonary arterial pressure (MPAP) is associated with poor prognosis in patients with idiopathic pulmonary fibrosis (IPF), yet the progression of MPAP in patients with IPF has not been sufficiently elucidated. We evaluated serial changes in MPAP and its determinants in patients with IPF with mild to moderate restriction.
MethodsWe retrospectively reviewed patients with IPF who underwent initial evaluations including right heart catheterization (RHC) in our institute from May 2007 to December 2013 with follow-up RHC at least 1year later. Patients with forced vital capacity (FVC)<50% predicted or those with pulmonary artery wedge pressure>15mm Hg were excluded.
ResultsA total of 95 patients were included. Median follow-up time of second RHC was 1.8years. MPAP increased significantly at follow-up (from 16.8 to 20.2mm Hg; P<0.001), and annual change in MPAP (MPAP) was 1.8mm Hg/year. In multiple regression analysis, the lowest oxygen saturation (SpO(2) ) at 6-min walk test (6MWT) was an independent predictor of MPAP. When adjusted for age, sex, baseline MPAP and FVC % predicted, MPAP was a significant predictor of mortality (hazard ratio: 1.21; P=0.001).
ConclusionMPAP was significantly associated with desaturation in the 6MWT, and with increased mortality in patients with IPF with mild to moderate restriction.
We reviewed patients with idiopathic pulmonary fibrosis with mild to moderate restriction and showed that mean pulmonary arterial pressure (MPAP) was progressive. The lowest oxygen saturation (SpO(2) ) in the 6-min walk test at baseline was an independent predictor of annual change in MPAP.

DOI： 10.1111/resp.12986

【MRI最前線】ガドリニウム造影剤と脳脊髄液 glymphaticシステムとは何か?

Effect of Gadolinium Deposition on 18F-FDG PET/CT of Dentate Nucleus and Globus Pallidus. Reviewed

Shinji Naganawa

J Nucl Med Technol. Vol. 45 ( 2 ) page： 173 2017.6

Letter to Editors: Detection of endolymphatic hydrops using traditional MR imaging sequences. Reviewed

Shinji Naganawa, Michihiko Sone

Am J Otolaryngol. ( 17 ) page： 30378-2 2017.6

FDG PET/CT Overcomes Discordance Between Clinical and Pathologic TNM Classification of Small-size Primary Lung Cancer: Influence on Postoperative Prognosis. Reviewed

Hiroyasu Umakoshi, Shingo Iwano, Kohei Yokoi, Shinji Ito, Rintaro Ito, Koji Kawaguchi, Takayuki Fukui, Shinji Naganawa

Clin Lung Cancer. ( 17 ) page： 30170-5 2017.6

Relationship between Contrast Enhancement of the Perivascular Space in the Basal Ganglia and Endolymphatic Volume Ratio. Reviewed

Toshio Ohashi, Shinji Naganawa, Toshio Katagiri, Kayao Kuno

Magn Reson Med Sci. 2017.6

田岡俊昭, 長縄慎二

臨床画像 Vol. 33 ( 6 ) page： 652 - 663 2017.6

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：(株)メジカルビュー社

2012年にNedergaardらにより,脳内の老廃物排出系としてのglymphaticシステムが提唱された。この仮説では血管周囲腔と,それを囲むグリアのエンドフィートを介した脳脊髄液による,脳組織の洗い流しによる老廃物の排出を想定している。この仮説と脳内のガドリニウム沈着の関連に関して考察したい。(著者抄録)

Other Link： https://search.jamas.or.jp/default/link?pub_year=2017&ichushi_jid=J01843&link_issn=&doc_id=20170605150003&doc_link_id=%2Fap4ringc%2F2017%2F003306%2F004%2F0652-0663%26dl%3D0&url=https%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fap4ringc%2F2017%2F003306%2F004%2F0652-0663%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Comparison of accumulation of F-18-FLT PET/CT with histopathological findings of primary and metastatic lesions of urinary tract tumors Reviewed

Katsuhiko Kato, Shinji Abe, Shinichiro Matsuzawa, Ryuto Mukumoto, Tetsuro Odagawa, Shinji Naganawa

JOURNAL OF NUCLEAR MEDICINE Vol. 58 page： . 2017.5

Portal Vein Bleeding after Pancreatectomy: Diagnosis and Stent Graft Repair - A Consecutive Case Series. Reviewed

Kojiro Suzuki, Tomoki Ebata, Tomohiro Komada, Masaya Matsushima, Takashi Mizuno, Tsuyoshi Igami, Gen Sugawara, Yukihiro Yokoyama, Shinji Naganawa, Masato Nagino

Journal of the Pancreas. Vol. 18 ( 3 ) page： 241-246 2017.5

Improved HYDROPS: Imaging of Endolymphatic Hydrops after Intravenous Administration of Gadolinium. Reviewed

Shinji Naganawa, Hisashi Kawai, Toshiaki Taoka, Michihiko Sone,

Magn Reson Med Sci. Vol. 16 ( 4 ) page： 357-361 2017.5

Structural MRI correlates of amyotrophic lateral sclerosis progression. Reviewed

J Neurol Neurosurg Psychiatry. Vol. 88 ( 11 ) page： 901-907 2017.5

Clinical outcome of definitive radiation therapy for superficial esophageal cancer. Reviewed

Yutaro Koide, Takeshi Kodaira, Hiroyuki Tachibana, Natsuo Tomita, Chiyoko Makita, Makoto Itoh, Tetsuya Abe, Kei Muro, Masahiro Tajika, Yasumasa Niwa, Yoshiyuki Itoh, Shinji Naganawa

Jpn J Clin Oncol. Vol. 47 ( 5 ) page： 393-400 2017.5

COPD Assessment Test for measurement of health status in patients with idiopathic pulmonary fibrosis: A cross-sectional study Reviewed

Toshiaki Matsuda, Hiroyuki Taniguchi, Masahiko Ando, Yasuhiro Kondoh, Tomoki Kimura, Kensuke Kataoka, Koji Sakamoto, Atsushi Suzuki, Taiki Furukawa, Yoshinori Hasegawa

RESPIROLOGY Vol. 22 ( 4 ) page： 721 - 727 2017.5

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY

Background and objectiveThe COPD Assessment Test (CAT) has been reported to have potential utility for measuring health status of idiopathic pulmonary fibrosis (IPF). Although the CAT has been developed for the assessment of COPD patients, it has not been fully evaluated exclusively in IPF. This study was designed to evaluate the validity of the CAT in IPF.
MethodsThe clinical data for 106 consecutive subjects with newly diagnosed IPF who completed pulmonary function tests, partial pressure of oxygen in arterial blood (PaO2 ) at rest, 6-min walk test (6MWT), CAT, St George's Respiratory Questionnaire (SGRQ), modified Medical Research Council (mMRC) dyspnoea grade and Hospital Anxiety and Depression Scale (HADS), were analysed. We assessed the validity of the CAT in comparison with the SGRQ.
ResultsThe present subjects showed mild to moderate restrictive impairment on spirometry. Mean CAT score and total SGRQ were 12.88.0 and 30.817.7, respectively. The concurrent validity of the CAT score in comparison with the SGRQ total score was significant (r=0.72, P<0.001). Internal consistency (Cronbach's =0.869) and repeatability over 3months (intraclass correlation coefficient=0.742) of the CAT were also significant. Single regression analysis showed that the CAT had significant construct validity. In multiple regression analysis, mMRC, PaO2 at rest, minimum SpO(2) during 6MWT and anxiety of HADS were independent predictors for the CAT.
ConclusionsThe CAT is a valid health status measurement in IPF patients. Multiple regression analysis showed that the CAT was significantly correlated with dyspnoea severity, oxygenation impairment and anxiety.
The validity of the COPD Assessment Test (CAT) was evaluated exclusively in idiopathic pulmonary fibrosis (IPF) patients in comparison with the St George's Respiratory Questionnaire (SGRQ). The CAT had a significant correlation with SGRQ and was independently predicted by dyspnoea severity, oxygenation impairment and anxiety.

DOI： 10.1111/resp.12936

Altered expression of ganglioside GM3 molecular species and a potential regulatory role during myoblast differentiation

Go Shinji, Go Shiori, Veillon Lucas, Ciampa Maria Grazia, Mauri Laura, Sato Chihiro, Kitajima Ken, Prinetti Alessandro, Sonnino Sandro, Inokuchi Jin-ichi

JOURNAL OF BIOLOGICAL CHEMISTRY Vol. 292 ( 17 ) page： 7040 - 7051 2017.4

Lack of Contrast Enhancement in a Giant Perivascular Space of the Basal Ganglion on Delayed FLAIR Images: Implications for the Glymphatic System. Reviewed Open Access

Shinji Naganawa, Toshiki Nakane, Hisashi Kawai, Toshiaki Taoka

Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine Vol. 16 ( 2 ) page： 89 - 90 2017.4

CSF Pulsation Artifacts on ADC Maps Obtained with Readout-segmented EPI.

Toshio Ohashi, Shinji Naganawa, Mai Kanou, Mitsuru Ikeda

Magn Reson Med Sci. Vol. 16 ( 2 ) page： 123-128 2017.4

Evaluation of glymphatic system activity with the diffusion MR technique: diffusion tensor image analysis along the perivascular space (DTI-ALPS) in Alzheimer's disease cases. Reviewed

Toshiaki Taoka, Yoshitaka Masutani, Hisashi Kawai, Toshiki Nakane, Kiwamu Matsuoka, Fumihiko Yasuno, Toshifumi Kishimoto, Shinji Naganawa

Jpn. J Radiol. ( 35 ) page： 172-178 2017.4

Lack of Contrast Enhancement in a Giant Perivascular Space of the Basal Ganglion on Delayed FLAIR Images: Implications for the Glymphatic System. Reviewed

Shinji Naganawa, Toshiki Nakane, Hisashi Kawai, Toshiaki Taoka

Magn Reson Med Sci. Vol. 16 ( 2 ) page： 89-90 2017.4

Evaluation of glymphatic system activity with the diffusion MR technique: diffusion tensor image analysis along the perivascular space (DTI-ALPS) in Alzheimer's disease cases. Reviewed Open Access

Toshiaki Taoka, Yoshitaka Masutani, Hisashi Kawai, Toshiki Nakane, Kiwamu Matsuoka, Fumihiko Yasuno, Toshifumi Kishimoto, Shinji Naganawa

Japanese journal of radiology Vol. 35 ( 4 ) page： 172 - 178 2017.4

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The activity of the glymphatic system is impaired in animal models of Alzheimer's disease (AD). We evaluated the activity of the human glymphatic system in cases of AD with a diffusion-based technique called diffusion tensor image analysis along the perivascular space (DTI-ALPS). MATERIALS AND METHODS: Diffusion tensor images were acquired to calculate diffusivities in the x, y, and z axes of the plane of the lateral ventricle body in 31 patients. We evaluated the diffusivity along the perivascular spaces as well as projection fibers and association fibers separately, to acquire an index for diffusivity along the perivascular space (ALPS-index) and correlated them with the mini mental state examinations (MMSE) score. RESULTS: We found a significant negative correlation between diffusivity along the projection fibers and association fibers. We also observed a significant positive correlation between diffusivity along perivascular spaces shown as ALPS-index and the MMSE score, indicating lower water diffusivity along the perivascular space in relation to AD severity. CONCLUSION: Activity of the glymphatic system may be evaluated with diffusion images. Lower diffusivity along the perivascular space on DTI-APLS seems to reflect impairment of the glymphatic system. This method may be useful for evaluating the activity of the glymphatic system.

DOI： 10.1007/s11604-017-0617-z

Magnetic resonance imaging evaluation of endolymphatic hydrops andpost-operative findings in cases with otosclerosis.

Michihiko Sone, Tadao Yoshida, Satofumi Sugimoto, Kyoko Morimoto, Yuriko Okazaki, Masaaki Teranishi, Shinji Naganawa, Tsutomu Nakashima

Acta Otolaryngol. Vol. 137 ( 3 ) page： 242-245 2017.3

Do gadolinium-based contrast agents affect the 18F-FDG PET/CT uptake in the dentate nucleus and the globus pallidus? Reviewed

Shinji Naganawa

J Nucl Med Technol. 2017.3

Modulation of immunological activity on macrophages induced by diazinon Reviewed

Nanako Ogasawara, Miyoko Matsushima, Nami Kawamura, Kazuko Atsumi, Takehiro Yamaguchi, Haruka Ochi, Yuto Kusatsugu, Sayaka Oyabu, Naozumi Hashimoto, Yoshinori Hasegawa, Jun Ueyama, Tsutomu Kawabe

TOXICOLOGY Vol. 379 page： 22 - 30 2017.3

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER IRELAND LTD

Diazinon is an organophosphorus (OP) insecticide and is widely used not only in agriculture but also homes and garden in Japan. Diazinon has been reported to increase TNF-alpha production in rat serum and brain, suggesting that it can modify the proinflammatory response. In this study, we investigated the effects of diazinon on macrophage functions, such as cytokine production, reactive oxygen species (ROS) generation, cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) expressions, cell-surface molecule expressions, and phagocytosis in RAW264.7 cells. In RAW264.7 cells, diazinon induced the production of TNF-alpha and IL-6. Diazinon induced ROS generation and the expressions of COX-2, iNOS, and cell-surface molecules CD40, CD86, and MI-IC class II, but reduced phagocytic activity in RAW264.7 cells. ERIC and p38, but not JNK and p65 were involved in diazinon-induced IL-6 expression in RAW264.7 cells. We also examined these proinflammatory responses in bone marrow-derived macrophages (BMDM) and bronchoalveolar lavage fluid (BALF) cells. These results suggested that diazinon can activate macrophages and enhance inflammatory responses. (C) 2017 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.tox.2017.01.014

FDG-PETによる非小細胞肺癌の予後予測因子の検討 SUVmaxと体積を考慮した指標の比較

Other Link： http://orcid.org/0000-0003-0660-2726

Emerging neuroradiological topics in journals from related societies. Reviewed

Yukunori Korogi, Shinji Naganawa

Jpn. J Radiol. Vol. 35 ( 1 ) page： 1-2 2017.2

Postoperative chemoradiation therapy using high dose cisplatin and fluorouracil for high- and intermediate-risk uterine cervical cancer. Reviewed

Rise Miyauchi, Yoshiyuki Itoh, Mariko Kawamura, Akihiro Hirakawa, Kiyosumi Shibata, Hiroaki Kajiyama, Rie Nakahara, Seiji Kubota, Junji Ito, Tohru Okada, Fumitaka Kikkawa, Shinji Naganawa

Nagoya J Med Sci. Vol. 79 ( 2 ) page： 211-220 2017.2

Imaging of the endolymphatic space in patients with Ménière's disease. Reviewed

Tadao Yoshida, Satofumi Sugimoto, Masaaki Teranishi, Hironao Otake, Masahiro Yamazaki, Shinji Naganawa, Tsutomu Nakashima, Michihiko Sone

Auris Nasus Larynx. ( 17 ) page： 30142-6 2017.2

Dual Energy CTによる小型肺癌の造影評価

島本宏矩, 岩野信吾, 馬越弘泰, 伊藤倫太郎, 長縄慎二

Japanese Journal of Radiology Vol. 35 ( Suppl. ) page： 34 - 34 2017.2

伊藤信嗣, 岩野信吾, 伊藤倫太郎, 長縄慎二, 加藤克彦

核医学 Vol. 54 ( 1 ) page： 565 - 565 2017.2

ドパミントランスポータシンチグラフィにおける解析ソフトの有用性に関する研究

松澤伸一郎, 加藤克彦, 国本啓太, 本田将之, 椋本竜斗, 小田川哲郎, 阿部真治, 藤田尚利, 櫻木庸博, 伊藤信嗣, 伊藤倫太郎, 岩野信吾, 長縄慎二

核医学 Vol. 54 ( 1 ) page： 663 - 663 2017.2

胸壁並行断面CTを用いた間質性肺炎の定量的評価

馬越弘泰, 岩野信吾, 伊藤倫太郎, 長縄慎二

Japanese Journal of Radiology Vol. 35 ( Suppl. ) page： 34 - 34 2017.2

Structure of the Medullary Veins of the Cerebral Hemisphere and Related Disorders. Reviewed

Toshiaki Taoka, Akio Fukuisumi, Toshiteru Miyasaka, Hisashi Kawai, Toshiki Nakane, Kimihiko Kichikawa, Shinji Naganawa

Radiographics. Vol. 37 ( 1 ) page： 281-297 2017.1

Endolymphatic hydrops in patients with unilateral and bilateral Meniere's disease.

Kyoko Morimoto, Tadao Yoshida, Saiko Sugiura, Masahiro Kato, Ken Kato, Masaaki Teranishi, Shinji Naganawa, Tsutomu Nakashima, Michihiko Sone

Acta Otolaryngol. Vol. 137 ( 1 ) page： 23-28 2017.1

Visualization of Middle Ear Ossicles in Elder Subjects with Ultra-short Echo Time MR Imaging

Shinji Naganawa, Toshiki Nakane, Hisashi Kawai, Toshiaki Taoka, Kojiro Suzuki, Shingo Iwano, Hiroko Satake, David Grodzki

MAGNETIC RESONANCE IN MEDICAL SCIENCES Vol. 16 ( 2 ) page： 93 - 97 2017

Language：English Publishing type：Research paper (scientific journal) Publisher：JPN SOC MAGNETIC RESONANCE MEDICINE

Purpose: To evaluate the visualization of middle ear ossicles by ultra-short echo time magnetic resonance (MR) imaging at 3T in subjects over 50 years old.
Materials and Methods: Sixty ears from 30 elder patients that underwent surgical or interventional treatment for neurovascular diseases were included (ages: 50-82, median age: 65; 10 men, 20 women). Patients received follow-up MR imaging including routine T1-and T2-weighted images, time-of-flight MR angiography, and ultra-short echo time imaging (PETRA, pointwise encoding time reduction with radial acquisition). All patients underwent computed tomography (CT) angiography before treatment. Thin-section source CT images were correlated with PETRA images. Scan parameters for PETRA were: TR 3.13, TE 0.07, flip angle 6 degrees, 0.83 x 0.83 x 0.83 mm resolution, 3 min 43 s scan time. Two radiologists retrospectively evaluated the visibility of each ossicular structure as positive or negative using PETRA images. The structures evaluated included the head of the malleus, manubrium of the malleus, body of the incus, long process of the incus, and the stapes. Signal intensity of the ossicles was classified as: between labyrinthine fluid and air, similar to labyrinthine fluid, between labyrinthine fluid and cerebellar parenchyma, or higher than cerebellar parenchyma.
Results: In all ears, the body of the incus was visible. The head of the malleus was visualized in 36/60 ears. The manubrium of the malleus and long process of the incus was visualized in 1/60 and 4/60 ears, respectively. The stapes were not visualized in any ear. Signal intensity of the visible structures was between labyrinthine fluid and air in all ears.
Conclusion: The body of the incus was consistently visualized with intensity between air and labyrinthine fluid on PETRA images in aged subjects. Poor visualization of the manubrium of the malleus, long process of the incus, and the stapes limits clinical significance of middle ear imaging with current PETRA methods.

DOI： 10.2463/mrms.mp.2015-0171

Gd-based Contrast Enhancement of the Perivascular Spaces in the Basal Ganglia

Shinji Naganawa, Toshiki Nakane, Hisashi Kawai, Toshiaki Taoka

MAGNETIC RESONANCE IN MEDICAL SCIENCES Vol. 16 ( 1 ) page： 61 - 65 2017

Language：English Publishing type：Research paper (scientific journal) Publisher：JPN SOC MAGNETIC RESONANCE IN MEDICINE

Purpose: In textbooks, the perivascular space (PVS) is described as non-enhancing after the intravenous administration of gadolinium-based contrast agent (IV-GBCA). We noticed that the PVS sometimes has high signal intensity (SI) on heavily T-2-weighted 3D-FLAIR (hT(2)-FL) images obtained 4 h after IV-GBCA. The purpose of this study was to retrospectively evaluate the contrast enhancement of the PVS.
Materials and Methods: In 8 healthy subjects and 19 patients with suspected endolymphatic hydrops, magnetic resonance cisternography (MRC) and hT(2)-FL images were obtained before and 4 h after a single dose of IV-GBCA. No subjects had renal insufficiency. On axial MRC at the level of the anterior commissure (AC)-posterior commissure (PC) line, 1 cm circular regions of interest (ROIs) were drawn centering on the PVS in the bilateral basal ganglia and thalami. Three-millimeter diameter ROIs were set in the cerebrospinal fluid (CSF) of the bilateral ambient cistern. The ROIs on MRC were copied onto the hT2-FL images and the SI was measured. The SI ratio (SIR) was defined as SIRPVS = SI of PVS/SI of the thalami, and SIRCSF = SI of CSF/SI of the thalami. The average of the bilateral values was used for the calculation. The SIRCSF, SIRPVS, and SI of the thalami were compared between before and 4 h after IV-GBCA.
Results: The SIR was increased significantly from 1.02 +/- 0.37 to 2.65 +/- 0.82 in the CSF (P < 0.01) and from 1.20 +/- 0.35 to 2.13 +/- 1.23 in the PVS at 4 h after IV-GBCA (P < 0.01). The SI of the thalami showed no significant difference.
Conclusion: The enhancement of the PVS at 4 h after IV-GBCA was confirmed even in subjects without renal insufficiency. It is possible that the GBCA in the blood vessels might have permeated into the cerebrospinal fluid (CSF) space and the PVS. This might be a first step in the imaging evaluation of the glymphatic system (waste clearance system) of the brain.

DOI： 10.2463/mrms.mp.2016-0039

Detection of endolymphatic hydrops using traditional MR imaging sequences

Naganawa Shinji, Sone Michihiko

AMERICAN JOURNAL OF OTOLARYNGOLOGY Vol. 38 ( 5 ) page： 637-638 2017

Quantitative evaluation of interstitial pneumonia using 3D-curved high-resolution CT imaging parallel to the chest wall: A pilot study. Reviewed International journal

Hiroyasu Umakoshi, Shingo Iwano, Tsutomu Inoue, Yuanzhong Li, Shinji Naganawa

PloS one Vol. 12 ( 9 ) page： e0185532 2017

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVES: To quantify the imaging findings of patients with interstitial pneumonia (IP) and emphysema using three-dimensional curved high-resolution computed tomography (3D-cHRCT) at a constant depth from the chest wall, and compare the results to visual assessment of IP and each patient's diffusing capacity of the lungs for carbon monoxide (DLco). METHODS: We retrospectively reviewed the axial CT findings and pulmonary function test results of 95 patients with lung cancer (72 men and 23 women, aged 45-84 years) with or without IP, as follows: non-IP (n = 47), mild IP (n = 31), and moderate IP (n = 17). The 3D-cHRCT images of the lung at a 1-cm depth from the chest wall were reconstructed automatically using original software; total area (TA), high-attenuation area (HAA) >-500 HU, and low-attenuation area (LAA) <-950 HU were calculated on a workstation. The %HAA and %LAA were calculated as follows: [Formula: see text], and [Formula: see text]. RESULTS: The %HAA and %LAA respective values were 3.2±0.9 and 27.7±8.2, 3.9±1.2 and 27.6±5.9, and 6.9±2.2 and 25.4±8.7 in non-IP, mild IP, and moderate IP patients, respectively. There were significant differences in %HAA between the 3 groups of patients (P<0.001), but no differences in %LAA (P = 0.558). Multiple linear regression analysis revealed that %HAA and %LAA were negatively correlated with predicted DLco (standard partial regression coefficient [b*] = -0.453, P<0.001; b* = -0.447, P<0.001, respectively). CONCLUSIONS: The %HAA and %LAA values computed using 3D-cHRCT were significantly correlated with DLco and may be important quantitative parameters for both IP and emphysema.

DOI： 10.1371/journal.pone.0185532

Thoracic Temporal Subtraction Three Dimensional Computed Tomography (3D-CT): Screening for Vertebral Metastases of Primary Lung Cancers. Reviewed International journal Open Access

Shingo Iwano, Rintaro Ito, Hiroyasu Umakoshi, Takatoshi Karino, Tsutomu Inoue, Yuanzhong Li, Shinji Naganawa

PloS one Vol. 12 ( 1 ) page： e0170309 2017

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: We developed an original, computer-aided diagnosis (CAD) software that subtracts the initial thoracic vertebral three-dimensional computed tomography (3D-CT) image from the follow-up 3D-CT image. The aim of this study was to investigate the efficacy of this CAD software during screening for vertebral metastases on follow-up CT images of primary lung cancer patients. MATERIALS AND METHODS: The interpretation experiment included 30 sets of follow-up CT scans in primary lung cancer patients and was performed by two readers (readers A and B), who each had 2.5 years' experience reading CT images. In 395 vertebrae from C6 to L3, 46 vertebral metastases were identified as follows: osteolytic metastases (n = 17), osteoblastic metastases (n = 14), combined osteolytic and osteoblastic metastases (n = 6), and pathological fractures (n = 9). Thirty-six lesions were in the anterior component (vertebral body), and 10 lesions were in the posterior component (vertebral arch, transverse process, and spinous process). The area under the curve (AUC) by receiver operating characteristic (ROC) curve analysis and the sensitivity and specificity for detecting vertebral metastases were compared with and without CAD for each observer. RESULTS: Reader A detected 47 abnormalities on CT images without CAD, and 33 of them were true-positive metastatic lesions. Using CAD, reader A detected 57 abnormalities, and 38 were true positives. The sensitivity increased from 0.717 to 0.826, and on ROC curve analysis, AUC with CAD was significantly higher than that without CAD (0.849 vs. 0.902, p = 0.021). Reader B detected 40 abnormalities on CT images without CAD, and 36 of them were true-positive metastatic lesions. Using CAD, reader B detected 44 abnormalities, and 39 were true positives. The sensitivity increased from 0.783 to 0.848, and AUC with CAD was nonsignificantly higher than that without CAD (0.889 vs. 0.910, p = 0.341). Both readers detected more osteolytic and osteoblastic metastases with CAD than without CAD. CONCLUSION: Our temporal 3D-CT subtraction CAD software easily detected vertebral metastases on the follow-up CT images of lung cancer patients regardless of the osteolytic or osteoblastic nature of the lesions.

DOI： 10.1371/journal.pone.0170309