研究者詳細 - 長縄　慎二

論文 - 長縄　慎二

分割表示 788 件中 261 - 280 件目／全件表示 >>

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. 査読有り

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 19 巻 ( 3 ) 頁： 168 - 175 2020年

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）

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. 査読有り

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 19 巻 ( 4 ) 頁： 333 - 344 2020年

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）

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. 査読有り国際誌

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

The British journal of radiology 93 巻 ( 1106 ) 頁： 20190712 - 20190712 2020年

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）

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 査読有り

Tsutsumi Yoshinori, Iwano Shingo, Okumura Naoki, Adachi Shiro, Abe Shinji, Kondo Takahisa, Kato Katsuhiko, Naganawa Shinji

JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY 44 巻 ( 4 ) 頁： 578 - 585 2020年

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. 査読有り

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 19 巻 ( 3 ) 頁： 235 - 246 2020年

記述言語：英語掲載種別：研究論文（学術雑誌）

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査読有り

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 - 巻 ( - ) 頁： 12 - 15 2019年12月

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― 査読有り

長縄慎二

月刊新医療 540 巻 ( - ) 頁： 77 - 77 2019年11月

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 59 巻 ( Suppl. ) 頁： S297 - S297 2019年11月

Balloon-Occluded Retrograde Transvenous Obliteration for Fundal Gastric Variceal Bleeding in a Small Child 査読有り国際誌

Komada, T; Suzuki, K; Oshima, K; Matsushima, M; Nagasaka, K; Naganawa, S

JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY 30 巻 ( 10 ) 頁： 1624 - 1625 2019年10月

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 40 巻 ( 10 ) 頁： 841 - 844 2019年10月

Glymphatic systemとMRI―ヒトでの可視化に向けた取り組み査読有り

長縄慎二

医学のあゆみ 270 巻 ( 13 ) 頁： 1189 - 1192 2019年10月

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 55回巻頁： S531 - S532 2019年9月

Reorganization of brain networks and its association with general cognitive performance over the adult lifespan 査読有り国際誌

Bagarinao, E; Watanabe, H; Maesawa, S; Mori, D; Hara, K; Kawabata, K; Yoneyama, N; Ohdake, R; Imai, K; Masuda, M; Yokoi, T; Ogura, A; Taoka, T; Koyama, S; Tanabe, HC; Katsuno, M; Wakabayashi, T; Kuzuya, M; Ozaki, N; Hoshiyama, M; Isoda, H; Naganawa, S; Sobue, G

SCIENTIFIC REPORTS 9 巻 ( 1 ) 頁： 11352 - 11352 2019年8月

High-dose-rate intracavitary brachytherapy for recurrent cervical cancer in the vaginal stump after hysterectomy 査読有り Open Access

Kozai, Y; Itoh, Y; Kawamura, M; Nakahara, R; Ito, J; Okada, T; Kikkawa, F; Ikeda, M; Naganawa, S

NAGOYA JOURNAL OF MEDICAL SCIENCE 81 巻 ( 3 ) 頁： 351 - 358 2019年8月

Whole abdominopelvic intensity-modulated radiation therapy for peritoneal disseminated rhabdomyosarcoma with three-year follow-up: a case report 査読有り国際誌

Kawamura, M; Okudaira, K; Itoh, Y; Kamomae, T; Nishikawa, E; Muramatsu, H; Takahashi, Y; Yokota, K; Naganawa, S

RADIATION ONCOLOGY 14 巻 ( 1 ) 頁： 127 - 127 2019年7月

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査読有り

伊藤倫太郎、岩野信吾、長縄慎二

INNERVISION 34 巻 ( 7 ) 頁： 25 - 28 2019年7月

Postoperative recurrence of clinical early-stage non-small cell lung cancers: a comparison between solid and subsolid nodules 査読有り国際誌

Iwano, S; Umakoshi, H; Kamiya, S; Yokoi, K; Kawaguchi, K; Fukui, T; Naganawa, S

CANCER IMAGING 19 巻 ( 1 ) 頁： 33 - 33 2019年6月

Monitoring of fatigue in radiologists during prolonged image interpretation using fNIRS 査読有り

Nihashi, T; Ishigaki, T; Satake, H; Ito, S; Kaii, O; Mori, Y; Shimamoto, K; Fukushima, H; Suzuki, K; Umakoshi, H; Ohashi, M; Kawaguchi, F; Naganawa, S

JAPANESE JOURNAL OF RADIOLOGY 37 巻 ( 6 ) 頁： 437 - 448 2019年6月

食道平滑筋腫査読有り

兵藤良太、岩野信吾、長縄慎二

画像診断 39 巻 ( 7 ) 頁： 662 - 663 2019年6月

【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 34 巻 ( 7 ) 頁： 25 - 28 2019年6月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：(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)

　前のページ - 次のページ　

<長縄 慎二>

論文 - 長縄 慎二

<長縄　慎二>

論文 - 長縄　慎二