Faculty Profiles - NAGANAWA, Shinji

Papers - NAGANAWA, Shinji

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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

Web of Science

PubMed

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

Web of Science

PubMed

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

Web of Science

PubMed

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

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

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

Web of Science

PubMed

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

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

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

Web of Science

PubMed

High-dose-rate intracavitary brachytherapy for recurrent cervical cancer in the vaginal stump after hysterectomy Reviewed

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

Web of Science

PubMed

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

Web of Science

PubMed

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

Web of Science

PubMed

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

Web of Science

PubMed

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

【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

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)

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Papers - NAGANAWA, Shinji