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

Authorship：Last author 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

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

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

Authorship：Last author 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

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

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

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

Authorship：Last author 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

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

Authorship：Last author 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

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

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

Maki S, Itoh Y, Kubota S, Okada T, Nakahara R, Ito J, Kawamura M, Naganawa S, Yoshino Y, Fujita T, Kato M, Gotoh M, Ikeda M

Journal of radiation research Vol. 58 ( 6 ) page： 870 - 880 2017.11

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

Clinical outcomes of <SUP>125</SUP>I brachytherapy with and without external-beam radiation therapy for localized prostate cancer: results from 300 patients at a single institution in Japan Reviewed

Maki, S; Itoh, Y; Kubota, S; Okada, T; Nakahara, R; Ito, J; Kawamura, M; Naganawa, S; Yoshino, Y; Fujita, T; Kato, M; Gotoh, M; Ikeda, M

JOURNAL OF RADIATION RESEARCH Vol. 58 ( 6 ) page： 870 - 880 2017.11

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

Authorship：Lead author,　Corresponding author 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

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 Reviewed

Clinical outcome of definitive radiation therapy for superficial esophageal cancer. Reviewed

Koide Y, Kodaira T, Tachibana H, Tomita N, Makita C, Itoh M, Abe T, Muro K, Tajika M, Niwa Y, Itoh Y, Naganawa S

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

Koide, Y; Kodaira, T; Tachibana, H; Tomita, N; Makita, C; Itoh, M; Abe, T; Muro, K; Tajika, M; Niwa, Y; Itoh, Y; Naganawa, S

JAPANESE JOURNAL OF CLINICAL ONCOLOGY Vol. 47 ( 5 ) page： 393 - 400 2017.5

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

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

Authorship：Last author 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