Updated on 2022/11/02

写真a

 
TAKEHARA Yasuo
 
Organization
Graduate School of Medicine Department of Fundamental Development for Advanced Low Invasive Diagnostic Imaging Endowed Chair Designated professor
Title
Designated professor

Degree 1

  1. 博士(医学) ( 1994.12   浜松医科大学 ) 

Research Interests 6

  1. contrast media

  2. flow analysis

  3. pancreaticobiliary diseases

  4. magnetic resonance in medicine

  5. 画像診断

  6. Diagnostic Imaging

Research Areas 1

  1. Life Science / Radiological sciences

Research History 14

  1. Department of fundamental development for advanced low invasive diagnostic imaging

    2016.10

  2. Hamamatsu University School of Medicine   University Hospital

    2011.1

  3. 浜松医科大学附属病院放射線部助教授

    2001.10

  4. - Associate professor and Vice-chairman of Radiology, Hamamatsu University Hospital

    2001

  5. 浜松医科大学附属病院放射線科講師

    1995.7

  6. 聖隷三方原病院放射線科医長、診療科長

    1991.4

  7. Hamamatsu University School of Medicine

    1989.10

  8. 米国カリフォルニア大学サンフランシスコ校 (UCSF)

    1988.7

  9. Department of Radiology, MRI division, 客員研究員(国際ロータリー財団奨学金)

    1988.7

  10. 社会福祉法人聖隷三方原病院放射線科 医員

    1987.4

  11. 同 助手

    1986.7

  12. 浜松医科大学附属病院放射線科医員

    1986.5

  13. 浜松医科大学附属病院放射線科医員(研修医)

    1984.5

  14. Hamamatsu University School of Medicine   School of Medicine, Faculty of Medicine

    1984.4

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Professional Memberships 12

  1. Radiological Society of North America

  2. International Society for Magnetic Resonance in Medicine

  3. 日本血管造形・インターベンショナルラジオロジー学会

  4. 日本膵臓学会

  5. The Japanese Society of Abdominal Radiology

  6. Japanese College of Angiology

  7. JAPAN BILIARY ASSOCIATION

  8. 日本磁気共鳴医学会

  9. 日本消化器病学会

  10. 日本核医学会

  11. 日本医学放射線学会

  12. ISMRM Japanese Chapter

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Committee Memberships 12

  1. 日本医学放射線学会   造影剤安全性委員会委員  

    2022.3   

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    Committee type:Academic society

  2. 4D Flow研究会   代表世話人  

    2019   

  3. 国際磁気共鳴医学会日本支部支部長   ISMRM Japanese Chapter Chairperson  

    2018 - 2019   

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    Committee type:Academic society

  4. Advanced Medical Imaging研究会(SAMI)   世話人  

    2016   

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    Committee type:Academic society

  5. 日本消化器画像診断研究会   世話人  

    2016   

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    Committee type:Academic society

  6. 日本医学放射線学会   学会誌Japanese Journal of Radiology編集委員  

    2002   

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    Committee type:Academic society

  7.   日本放射線科医会・専門医会 理事  

    2002 - 2020   

  8.   European Congress of Radiology, 学会誌European Radiology編集委員(欧州連合)  

    2002   

  9.   Editor of “Japanese Journal of Radiology” (official Journal of Japanese Radiological Society)  

       

  10. 日本腹部放射線学会   理事  

       

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    Committee type:Academic society

  11.   日本医学放射線学会 代議員  

       

  12. 日本磁気共鳴医学会   理事 学会誌Magnetic Resonance in Medical Sciences編集委員  

       

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    Committee type:Academic society

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Awards 1

  1. Best Paper Award, Japanese Society for Magnetic Resonance in Medicine

    2021.9   Japanese Society for Magnetic Resonance in Medicine   Magn Reson Med Sci. 2020 Aug 3;19(3):235-246. 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

    Takehara Y, Isoda H, Takahashi M, Unno N, Shiiya N, Ushio T, Goshima S, Naganawa S, Alley M, Wakayama T, Nozaki A

 

Papers 48

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

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    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

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  2. 4D Flow MRI in the portal venous system: imaging and analysis methods, and clinical applications.

    Hyodo R, Takehara Y, Naganawa S

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

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    Language:English   Publisher:Radiologia Medica  

    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

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  3. Four-dimensional flow magnetic resonance imaging visualizes reverse vortex pattern and energy loss increase in left bundle branch block. Reviewed International journal

    Keisuke Miyajima, Tsuyoshi Urushida, Kazuki Ito, Fumihiko Kin, Ayako Okazaki, Yasuyo Takashima, Tomoyuki Watanabe, Yoshitaka Kawaguchi, Yasushi Wakabayashi, Yasuo Takehara, Yuichiro Maekawa

    Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology   Vol. 24 ( 8 ) page: 1284 - 1290   2022.9

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    AIMS: This study aimed to investigate the intraventricular blood flow pattern of patients with left bundle branch block (LBBB) using four-dimensional flow magnetic resonance imaging (4D-flow MRI). METHODS AND RESULTS: We performed 4D-flow MRI for 16 LBBB patients (LBBB group) and 16 propensity score-matched patients with a normal QRS duration (non-LBBB group). The energy loss (EL) in the left ventricle was evaluated. In both groups, blood flow from the mitral valve to the apex of the heart and left ventricular (LV) outflow tract during LV diastole were observed. Vortices were also observed in both groups. There were two patterns of vortices: unidirectional clockwise rotation and counterclockwise rotation taking place from the mid-diastole to the systole (reverse pattern). The reverse pattern was observed significantly more frequently in the LBBB group (LBBB 94% vs. non-LBBB 19%, P < 0.001). The interobserver agreement for the streamline analysis was good (kappa = 0.68). The maximum EL was significantly higher in the LBBB group [LBBB 12 (11-15) mW vs. non-LBBB 8.0 (6.2-9.7) mW, P < 0.001]. CONCLUSION: Left bundle branch block patients may suffer from inefficient LV haemodynamics reflected by non-physiological counterclockwise vortices and increased EL. Thus, the shape of the vortices and EL in the left ventricle can serve as markers of LV mechanical dyssynchrony in LBBB patients and could be investigated as predictors of response to cardiac resynchronization therapy.

    DOI: 10.1093/europace/euab299

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  4. Postendovascular Aneurysmal Repair Increase in Local Energy Loss for Fusiform Abdominal Aortic Aneurysm: Assessments With 4D flow MRI 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     2022.7

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

    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

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  5. Why 4D Flow MRI? Real Advantages.

    Yasuo Takehara, Tetsuro Sekine, Takayuki Obata

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 21 ( 2 ) page: 253 - 256   2022.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JPN SOC MAGNETIC RESONANCE MEDICINE  

    This special issue of Magnetic Resonance in Medical Sciences features the most recent reviews on 4D Flow MRI. These reviews deal with the current status of the emerging technique of 4D Flow MRI facilitated in various areas that are difficult to obtain with conventional flowmetry. MR signals inherently contain flow velocity information. In previous decades, in vivo blood flow measurement was traditionally performed by 2D methods, such as Doppler ultrasonography and 2D phase-contrast MRI, which have long been regarded as mature techniques in hemodynamic flowmetry. Although 2D velocimetries have many advantages over 4D Flow MRI in terms of cost and accessibility, and provide excellent temporal and in-plane spatial resolutions, they also have some disadvantages. The emerging technology of 4D Flow MRI can overcome the shortcomings of conventional 2D imaging. In recent years, hemodynamic analysis has witnessed significant progress that is primarily attributable to advances in 4D Flow MRI.

    DOI: 10.2463/mrms.e.2022-1000

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  6. Clinical Application of 4D Flow MR Imaging for the Abdominal Aorta.

    Yasuo Takehara

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 21 ( 2 ) page: 354 - 364   2022.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JPN SOC MAGNETIC RESONANCE MEDICINE  

    Blood vessels can be regarded as autonomous organs. The endothelial cells on the vessel surface serve as mechanosensors or mechanoreceptors for the flow velocity and turbulence of the blood flow in terms of wall shear stress (WSS), thereby monitoring changes in the flow velocity. Accordingly, the endothelial cells regulate the flow velocity by releasing numerous mediators. Such regulatory systems also trigger atherosclerosis, where the WSS decreases or fluctuates to maintain the flow velocity or local WSS. As occurrences of abdominal aortic aneurysms and aortic dissection are closely related to atherosclerosis, understanding the hemodynamics of the abdominal aorta is necessary to obtain useful information concerning the pathogenesis, diagnosis, and interventions. 4D flow MRI is beneficial for measuring the hemodynamics through comprehensive retrospective flowmetry of the entire spatio-temporal distributions of the flow vectors. This section focuses on abdominal aortic aneurysms and aortic dissection as representative examples of abdominal aortic diseases. Their hemodynamic characteristics and how hemodynamics is involved in their progression are described, and how 4D flow MRI can contribute to their assessment is also explained.

    DOI: 10.2463/mrms.rev.2021-0156

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

    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

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    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

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  8. Hemodynamic Parameters for Cardiovascular System in 4D Flow MRI: Mathematical Definition and Clinical Applications.

    Keiichi Itatani, Tetsuro Sekine, Masaaki Yamagishi, Yoshinobu Maeda, Norika Higashitani, Shohei Miyazaki, Junya Matsuda, Yasuo Takehara

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 21 ( 2 ) page: 380 - 399   2022.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JPN SOC MAGNETIC RESONANCE MEDICINE  

    Blood flow imaging becomes an emerging trend in cardiology with the recent progress in computer technology. It not only visualizes colorful flow velocity streamlines but also quantifies the mechanical stress on cardiovascular structures; thus, it can provide the detailed inspections of the pathophysiology of diseases and predict the prognosis of cardiovascular functions. Clinical applications include the comprehensive assessment of hemodynamics and cardiac functions in echocardiography vector flow mapping (VFM), 4D flow MRI, and surgical planning as a simulation medicine in computational fluid dynamics (CFD).For evaluation of the hemodynamics, novel mathematically derived parameters obtained using measured velocity distributions are essential. Among them, the traditional and typical parameters are wall shear stress (WSS) and its related parameters. These parameters indicate the mechanical damages to endothelial cells, resulting in degenerative intimal change in vascular diseases. Apart from WSS, there are abundant parameters that describe the strength of the vortical and/or helical flow patterns. For instance, vorticity, enstrophy, and circulation indicate the rotating flow strength or power of 2D vortical flows. In addition, helicity, which is defined as the cross-linking number of the vortex filaments, indicates the 3D helical flow strength and adequately describes the turbulent flow in the aortic root in cases with complicated anatomies. For the description of turbulence caused by the diseased flow, there exist two types of parameters based on completely different concepts, namely: energy loss (EL) and turbulent kinetic energy (TKE). EL is the dissipated energy with blood viscosity and evaluates the cardiac workload related to the prognosis of heart failure. TKE describes the fluctuation in kinetic energy during turbulence, which describes the severity of the diseases that cause jet flow. These parameters are based on intuitive and clear physiological concepts, and are suitable for in vivo flow measurements using inner velocity profiles.

    DOI: 10.2463/mrms.rev.2021-0097

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  9. Technical Background for 4D Flow MR Imaging.

    Masaki Terada, Yasuo Takehara, Haruo Isoda, Tetsuya Wakayama, Atsushi Nozaki

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 21 ( 2 ) page: 267 - 277   2022.3

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    Recently, the hemodynamic assessments with 3D cine phase-contrast (PC) MRI (4D flow MRI) have attracted considerable attention from clinicians. Unlike 2D cine PC MRI, the technique allows for cardiac phase-resolved data acquisitions of flow velocity vectors within the entire FOV during a clinically viable period. Thus, the method has enabled retrospective flowmetry in the spatial and temporal axes, which are essential to derive hemodynamic parameters related to vascular homeostasis and those to the progression of the pathologies. Accelerations in imaging are critical for this technology to be clinically viable; however, a high SNR or velocity-to-noise ratio (VNR) is also vital for accurate flow measurements. In this chapter, the technologies enabling this difficult balance are discussed.

    DOI: 10.2463/mrms.rev.2021-0104

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  10. 特集 膵癌早期診断のイノベーションを求めて 早期膵癌のMRCP

    小川 浩, 竹原 康雄, 長縄 慎二

    画像診断   Vol. 42 ( 3 ) page: 271 - 278   2022.2

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    Publisher:学研メディカル秀潤社  

    DOI: 10.15105/gz.0000002683

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  11. 特集 膵癌早期診断のイノベーションを求めて 序説にかえて

    竹原 康雄, 蒲田 敏文

    画像診断   Vol. 42 ( 3 ) page: 247 - 251   2022.2

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    DOI: 10.15105/gz.0000002680

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  12. Consensus-Based Technical Recommendations for Clinical Translation of Renal Phase Contrast MRI. Reviewed International journal

    Anneloes de Boer, Giulia Villa, Octavia Bane, Michael Bock, Eleanor F Cox, Ilona A Dekkers, Per Eckerbom, Maria A Fernández-Seara, Susan T Francis, Bryan Haddock, Michael E Hall, Pauline Hall Barrientos, Ingo Hermann, Paul D Hockings, Hildo J Lamb, Christoffer Laustsen, Ruth P Lim, David M Morris, Steffen Ringgaard, Suraj D Serai, Kanishka Sharma, Steven Sourbron, Yasuo Takehara, Andrew L Wentland, Marcos Wolf, Frank G Zöllner, Fabio Nery, Anna Caroli

    Journal of magnetic resonance imaging : JMRI   Vol. 55 ( 2 ) page: 323 - 335   2022.2

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    BACKGROUND: Phase-contrast (PC) MRI is a feasible and valid noninvasive technique to measure renal artery blood flow, showing potential to support diagnosis and monitoring of renal diseases. However, the variability in measured renal blood flow values across studies is large, most likely due to differences in PC-MRI acquisition and processing. Standardized acquisition and processing protocols are therefore needed to minimize this variability and maximize the potential of renal PC-MRI as a clinically useful tool. PURPOSE: To build technical recommendations for the acquisition, processing, and analysis of renal 2D PC-MRI data in human subjects to promote standardization of renal blood flow measurements and facilitate the comparability of results across scanners and in multicenter clinical studies. STUDY TYPE: Systematic consensus process using a modified Delphi method. POPULATION: Not applicable. SEQUENCE FIELD/STRENGTH: Renal fast gradient echo-based 2D PC-MRI. ASSESSMENT: An international panel of 27 experts from Europe, the USA, Australia, and Japan with 6 (interquartile range 4-10) years of experience in 2D PC-MRI formulated consensus statements on renal 2D PC-MRI in two rounds of surveys. Starting from a recently published systematic review article, literature-based and data-driven statements regarding patient preparation, hardware, acquisition protocol, analysis steps, and data reporting were formulated. STATISTICAL TESTS: Consensus was defined as ≥75% unanimity in response, and a clear preference was defined as 60-74% agreement among the experts. RESULTS: Among 60 statements, 57 (95%) achieved consensus after the second-round survey, while the remaining three showed a clear preference. Consensus statements resulted in specific recommendations for subject preparation, 2D renal PC-MRI data acquisition, processing, and reporting. DATA CONCLUSION: These recommendations might promote a widespread adoption of renal PC-MRI, and may help foster the set-up of multicenter studies aimed at defining reference values and building larger and more definitive evidence, and will facilitate clinical translation of PC-MRI. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 1.

    DOI: 10.1002/jmri.27419

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  13. Construction of an Endothelial Cell Alignment Model for Prediction of Abdominal Aortic Aneurysm Growth

    ITO Jumpei, TERAHARA Takuya, SAITO Yoku, AZUMA Hayato, ISHIDA Katsuya, TAKIZAWA Kenji, TEZDUYAR Tayfun E., TAKEHARA Yasuo

    The Proceedings of the JSME Conference on Frontiers in Bioengineering   Vol. 2022.32 ( 0 ) page: 2C20   2022

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    Language:Japanese   Publisher:The Japan Society of Mechanical Engineers  

    DOI: 10.1299/jsmebiofro.2022.32.2c20

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  14. 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. advpub ( 0 )   2021.12

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

    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

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  15. 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   2021.12

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

    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

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

    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. advpub ( 0 )   2021.10

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    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.

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

    Hiroshi Ogawa, Yasuo Takehara, Shinji Naganawa

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

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    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.

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  18. 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   2021.9

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    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.

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  19. 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

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

    HEPATOLOGY RESEARCH   Vol. 51 ( 3 ) page: 343 - 349   2021.3

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  20. Daikenchuto increases blood flow in the superior mesenteric artery in humans: A comparison study between four-dimensional phase-contrast vastly undersampled isotropic projection reconstruction magnetic resonance imaging and Doppler ultrasound. Reviewed International journal

    Katsunori Suzuki, Yasuo Takehara, Mayu Sakata, Masanori Kawate, Naoki Ohishi, Kosuke Sugiyama, Toshiya Akai, Yuhi Suzuki, Masataka Sugiyama, Takafumi Kawamura, Yoshifumi Morita, Hirotoshi Kikuchi, Yoshihiro Hiramatsu, Masayoshi Yamamoto, Hatsuko Nasu, Kevin Johnson, Oliver Wieben, Kiyotaka Kurachi, Hiroya Takeuchi

    PloS one   Vol. 16 ( 1 ) page: e0245878   2021

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    Respiratory-gated four-dimensional phase-contrast vastly undersampled isotropic projection reconstruction (4D PC-VIPR) is magnetic resonance (MR) imaging technique that enables analysis of vascular morphology and hemodynamics in a single examination using cardiac phase resolved 3D phase-contrast magnetic resonance imaging. The present study aimed to assess the usefulness of 4D PC-VIPR for the superior mesenteric artery (SMA) flowmetry before and after flow increase was induced by the herbal medicine Daikenchuto (TJ-100) by comparing it with Doppler ultrasound (DUS) as a current standard. Twenty healthy volunteers were enrolled in this prospective single-arm study. The peak cross-sectionally averaged velocity was measured by 4D PC-VIPR, peak velocity was measured by DUS, and flow volume (FV) of SMA and aorta were measured by 4D PC-VIPR and DUS 25 min before and after the peroral administration of TJ-100. The peak cross-sectionally averaged velocity, peak velocity, and FV of SMA measured by 4D PC-VIPR and DUS significantly increased after administration of TJ-100 (4D PC-VIPR: the peak cross-sectionally averaged velocity; p = 0.004, FV; p = 0.035, DUS: the peak velocity; p = 0.003, FV; p = 0.010). Furthermore, 4D PC-VIPR can analyze multiple blood vessels simultaneously. The ratio of the SMA FV to the aorta, before and after oral administration on the 4D PC-VIPR test also increased (p = 0.015). The rate of change assessed by 4D PC-VIPR and DUS were significantly correlated (the peak cross-sectionally averaged velocity and peak velocity: r = 0.650; p = 0.005, FV: r = 0.659; p = 0.004). Retrospective 4D PC-VIPR was a useful modality for morphological and hemodynamic analysis of SMA.

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  21. How Memory Switches Brain Responses of Patients with Post-traumatic Stress Disorder. Reviewed International journal

    Jun Inoue, Kayako Matsuo, Toshiki Iwabuchi, Yasuo Takehara, Hidenori Yamasue

    Cerebral cortex communications   Vol. 2 ( 2 ) page: tgab021   2021

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    To characterize the brain responses to traumatic memories in post-traumatic stress disorder (PTSD), we conducted task-employed functional magnetic resonance imaging and, in the process, devised a simple but innovative approach-correlation computation between task conditions. A script-driven imagery task was used to compare the responses with a script of the patients' own traumatic memories and with that of tooth brushing as a daily activity and to evaluate how eye movement desensitization and reprocessing (EMDR), an established therapy for PTSD, resolved the alterations in patients. Nine patients with PTSD (seven females, aged 27-50 years) and nine age- and gender-matched healthy controls participated in this study. Six patients underwent the second scan under the same paradigm after EMDR. We discovered intense negative correlations between daily and traumatic memory conditions in broad areas, including the hippocampus; patients who had an intense suppression of activation during daily recognition showed an intense activation while remembering a traumatic memory, whereas patients who had a hyperarousal in daily recognition showed an intense suppression while remembering a traumatic memory as a form of "shut-down." Moreover, the magnitude of the discrepancy was reduced in patients who remitted after EMDR, which might predict an improved prognosis of PTSD.

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  22. 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   2020.12

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    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.

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  23. 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   2020.12

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    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.

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  24. 特集 画像診断に必要なartifactsの知識 MRIにおける注意すべきartifacts

    寺田 理希, 竹原 康雄

    臨床放射線   Vol. 65 ( 12 ) page: 1275 - 1294   2020.11

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    DOI: 10.18888/rp.0000001434

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  25. 4D Flow when and how? Reviewed International journal

    Yasuo Takehara

    La Radiologia medica   Vol. 125 ( 9 ) page: 838 - 850   2020.9

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    4D Flow is an emerging MR technique enabling three-dimensional and cardiac phase-resolved flowmetry with ECG-gated phase-contrast MRI that increased the speed of data acquisitions, accuracy and robustness. The method is promoting researches in areas that have not been fully addressed before in the cardiovascular system, such as flowmetry of the bloodstream across the valves, within the heart chambers, complexed flow dynamics such as vortex, helical or retrograde. Wall shear stress and other potential biomarkers derived from 4D Flow are known to be related to vascular wall diseases such as atherosclerosis. In this review, fundamental concepts of 4D Flow technique and post-processing, benefits and limitations as well as its clinical applications are discussed, and the importance of quality control and validation of the method is emphasized. New ideas inspired by 4D Flow can help clinicians and MR scientists further understand the role of flow dynamics in health sciences, diseases and various aspects of cardiovascular physiology.

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  26. 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   2020.8

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    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.

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  27. Intravoxel incoherent motion magnetic resonance imaging for predicting the long-term efficacy of immune checkpoint inhibitors in patients with non-small-cell lung cancer. Reviewed International journal

    Masato Karayama, Nobuko Yoshizawa, Masataka Sugiyama, Kazutaka Mori, Hideki Yasui, Hironao Hozumi, Yuzo Suzuki, Kazuki Furuhashi, Tomoyuki Fujisawa, Noriyuki Enomoto, Yutaro Nakamura, Naoki Inui, Satoshi Goshima, Takafumi Suda, Yasuo Takehara

    Lung cancer (Amsterdam, Netherlands)   Vol. 143   page: 47 - 54   2020.5

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    OBJECTIVES: Conventional evaluation of anti-tumor activity on the basis of tumor size is inadequate for immune checkpoint inhibitors (ICIs). We therefore aimed to assess the usefulness of intravoxel incoherent motion magnetic resonance imaging (IVIM-MRI) for evaluation of the therapeutic efficacy of ICIs. MATERIALS AND METHODS: A chest IVIM-MRI was performed before and 2, 4, and 8 weeks after administration of ICIs in patients with advanced non-small-cell lung cancer. Apparent diffusion coefficient (ADC), skewness of ADC (ADCskew), kurtosis of ADC (ADCkurt), true diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) were evaluated at each evaluation point and changes from the baseline (Δ). RESULTS: Twenty patients were enrolled in this study. An increased ADC 8 weeks and decreased ADCkurt and ΔADCkurt 4 weeks after ICIs was associated with objective responses and longer progression-free survival (PFS). A decreased ΔADCskew at 4 weeks was associated with objective responses, disease control, and longer PFS and overall survival. There was no correlation between the efficacy of ICIs and D, D* and f. All of three patients who had pseudoprogression had decreased ΔADCskew at 4 weeks and two of them had decreased ΔADCkurt at 4 weeks. Inversely, all five patients who had progressive disease (PD) did not have increased ΔADCskew at 4 weeks and only one of them had decreased ΔADCkurt at 4 weeks. CONCLUSIONS: Changes in histograms of ADC may be useful for predicting long-term efficacy and distinguishing between pseudoprogression and actual PD after ICIs.

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

    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

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    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.

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  29. Motion and solution in hepatobiliary agent-enhanced dynamic MRI: solid evidence and unanswered question

    Utaroh Motosugi, Yasuo Takehara

    JAPANESE JOURNAL OF RADIOLOGY   Vol. 38 ( 2 ) page: 99 - 100   2020.2

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  30. 特集 MRIで読み解く 心臓と脈管:流れと機能 腹部大動脈瘤の4D–flow

    杉山 将隆, 竹原 康雄

    臨床画像   Vol. 36 ( 1 ) page: 42 - 48   2020.1

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    DOI: 10.18885/ci.0000000106

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  31. Accuracy of the Flow Velocity and Three-directional Velocity Profile Measured with Three-dimensional Cine Phase-contrast MR Imaging: Verification on Scanners from Different Manufacturers. Reviewed

    Tomoya Watanabe, Haruo Isoda, Atushi Fukuyama, Mamoru Takahashi, Tomoyasu Amano, Yasuo Takehara, Naoki Oishi, Masanori Kawate, Masaki Terada, Takafumi Kosugi, Yoshiaki Komori, Yukiko Fukuma, Marcus Alley

    Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine   Vol. 18 ( 4 ) page: 265 - 271   2019.10

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    PURPOSE: The accuracy of flow velocity and three-directional velocity components are important for the precise visualization of hemodynamics by 3D cine phase-contrast MRI (3D cine PC MRI, also referred to as 4D-flow). The aim of this study was to verify the accuracy of these measurements of prototype or commercially available 3D cine PC MRI obtained by three different manufactures' MR scanners. METHODS: The verification of the accuracy of flow velocity in 3D cine PC MRI was performed by circulating blood mimicking fluid through a straight-tube phantom in a slanting position, such that the three-directional velocity components were simultaneously measurable, using three 3T MR scanners from different manufacturers. The data obtained were processed by phase correction, and the velocity and three-directional velocity components in the center of the tube on the central cross section of a slab were calculated. The velocity profile in each three directions and the composite velocity profiles were compared with the calculated reference values, using the Hagen-Poiseuille equation. In addition, velocity profiles and the spatially time-averaged velocity perpendicular to the tube were compared with the theoretical values and measured values by a flowmeter, respectively. RESULTS: An underestimation of the maximum velocity in the center of the tube and an overestimation of the velocity near the tube wall due to partial volume effects were observed in all three scanners. A roughening and flattening of profiles in the center of the tube were observed in one scanner, due, presumably, to the low signal-to-noise ratio. However, the spatially time-averaged velocities corresponded well with the measured values by the flowmeter in all three scanners. CONCLUSION: In this study, we have demonstrated that the accuracy of flow velocity and three-directional velocity components in 3D cine PC MRI was satisfactory in all three MR scanners.

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  32. Mechanical haemolytic anaemia assessed with four-dimensional flow cardiac magnetic resonance. Reviewed International journal

    Wataru Uchida, Yoshiyuki Tokuda, Yasuo Takehara, Akihiko Usui

    European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery   Vol. 56 ( 4 ) page: 813 - 814   2019.10

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    A 66-year-old woman developed marked haemolytic anaemia 2 years after total aortic arch replacement using a branched Dacron graft. Echocardiography confirmed bicuspid aortic valve stenosis. A four-dimensional flow magnetic resonance imaging revealed a jet flow arising from the aortic valve along with the vortex and turbulent flow inside the kinked prosthetic graft at the ascending aorta. She underwent a reoperation to replace the aortic valve and correct the kinking. The estimated energy loss after intervention was relieved to 2.9 mJ/cardiac cycle from 4.3 mJ/cardiac cycle before intervention. The patient's anaemia resolved immediately after the reoperation.

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  33. Flow dynamics of type II endoleaks can determine sac expansion after endovascular aneurysm repair using four-dimensional flow-sensitive magnetic resonance imaging analysis. Reviewed International journal

    Kazuto Katahashi, Masaki Sano, Yasuo Takehara, Kazunori Inuzuka, Masataka Sugiyama, Marcus T Alley, Hiroya Takeuchi, Naoki Unno

    Journal of vascular surgery   Vol. 70 ( 1 ) page: 107 - 116.e1   2019.7

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    OBJECTIVE: The objective of this study was to investigate the hemodynamic parameters of type II endoleaks (T2ELs) to predict sac expansion using four-dimensional flow-sensitive magnetic resonance imaging (4D-flow MRI) analysis. METHODS: Patients who underwent endovascular aneurysm repair (EVAR) and were diagnosed with a T2EL were included in the study. Using 4D-flow MRI at 7 days, the peak flow velocity and amplitude of dynamics of blood flow per minute were measured in each T2EL vessel. The peak flow velocity was defined as the maximum of the absolute value of the blood flow velocity. The amplitude of dynamics of blood flow in the tributary arteries was defined as the sum of the absolute values of the inflow and outflow volume in each vessel. The amplitude of dynamics of blood flow in the tributary arteries per sac was calculated in each sac. The aneurysm sac diameter was measured by computed tomography (CT) at 1 year. The patients were divided into two groups according to the presence or absence of sac expansion. RESULTS: Of 155 patients who underwent EVAR, both CT angiography and 4D-flow MRI were performed in 107 patients at 7 days after EVAR. Among them, 39 (36.4%) were found to have a T2EL, of whom 28 were re-evaluated with CT angiography and 4D-flow at 1 year; 7 patients had expanding sacs (expanding group), whereas 21 had nonexpanding sacs (not-expanding group). At 7 days, 28 patients had 80 T2EL vessels detected by 4D-flow MRI, of which 39 vessels (48.8%) had stopped flowing at 1 year (transient vessels); 41 vessels (51.3%) had sustained flow (persistent vessels). The persistent vessels had significantly larger peak flow velocity and amplitude of dynamics of blood flow. The comprehensive analysis of T2EL vessels per sac identified that the amplitude of dynamics of blood flow in the tributary arteries per sac was significantly higher in the expanding group than in the not-expanding group. A receiver operating characteristic curve analysis revealed that the sensitivity and specificity of sac enlargement at a cutoff value of 3750 mm3/min were 85.7% and 76.2%, respectively. CONCLUSIONS: The fate of aneurysm sacs with T2ELs after EVAR has remained difficult to predict. A comprehensive analysis of concurrent multiple T2EL vessels using 4D-flow MRI analysis may enable prediction of the sac expansion after EVAR.

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  34. A case of human pancreatic eurytremiasis. International journal

    Hiroshi Ogawa, Yasuo Takehara, Shinji Naganawa, Junpei Yamaguchi, Masato Nakaguro

    Abdominal radiology (New York)   Vol. 44 ( 4 ) page: 1213 - 1216   2019.4

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    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

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  35. 特集 全身拡散強調画像の歴史と発展 全身拡散強調画像の歴史と発展-序文にかえて

    竹原 康雄

    臨床放射線   Vol. 64 ( 3 ) page: 213 - 214   2019.3

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    DOI: 10.18888/rp.0000000775

    CiNii Research

  36. 膵癌update Ⅱ 診断 ⑥MRI/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   2018.5

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    DOI: 10.19020/cg.0000000391

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  37. Hemodynamic vascular biomarkers for initiation of paraclinoid internal carotid artery aneurysms using patient-specific computational fluid dynamic simulation based on magnetic resonance imaging International journal

    Tomoya Watanabe, Haruo Isoda, Yasuo Takehara, Masaki Terada, Takehiro Naito, Takafumi Kosugi, Yuki Onishi, Chiharu Tanoi, Takashi Izumi

    Neuroradiology   Vol. 60 ( 5 ) page: 545 - 555   2018.5

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    Purpose: We performed computational fluid dynamics (CFD) for patients with and without paraclinoid internal carotid artery (ICA) aneurysms to evaluate the distribution of vascular biomarkers at the aneurysm initiation sites of the paraclinoid ICA. Methods: This study included 35 patients who were followed up for aneurysms using 3D time of flight (TOF) magnetic resonance angiography (MRA) and 3D cine phase-contrast MR imaging. Fifteen affected ICAs were included in group A with the 15 unaffected contralateral ICAs in group B. Thirty-three out of 40 paraclinoid ICAs free of aneurysms and arteriosclerotic lesions were included in group C. We deleted the aneurysms in group A based on the 3D TOF MRA dataset. We performed CFD based on MR data set and obtained wall shear stress (WSS), its derivatives, and streamlines. We qualitatively evaluated their distributions at and near the intracranial aneurysm initiation site among three groups. We also calculated and compared the normalized highest (nh-) WSS and nh-spatial WSS gradient (SWSSG) around the paraclinoid ICA among three groups. Results: High WSS and SWSSG distribution were observed at and near the aneurysm initiation site in group A. High WSS and SWSSG were also observed at similar locations in group B and group C. However, nh-WSS and nh-SWSSG were significantly higher in group A than in group C, and nh-SWSSG was significantly higher in group A than in group B. Conclusion: Our findings indicated that nh-WSS and nh-SWSSG were good biomarkers for aneurysm initiation in the paraclinoid ICA.

    DOI: 10.1007/s00234-018-2002-8

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  38. 【大動脈疾患の画像診断:画像所見・画像からみた自然史・治療効果判定】 大動脈疾患のMRI. Reviewed

    竹原 康雄

    臨床画像   Vol. 34 ( 1 ) page: 40-52   2018

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  39. Four-dimensional phase-contrast vastly undersampled isotropic projection reconstruction (4D PC-VIPR) MR evaluation of the renal arteries in transplant recipients: Preliminary results Reviewed International journal

    Daisuke Motoyama, Yasuo Ishii, Yasuo Takehara, Masataka Sugiyama, Wang Yang, Hatsuko Nasu, Takasuke Ushio, Yuko Hirose, Naoki Ohishi, Tetsuya Wakayama, Hiroyuki Kabasawa, Kevin Johnson, Oliver Wieben, Harumi Sakahara, Seiichiro Ozono

    JOURNAL OF MAGNETIC RESONANCE IMAGING   Vol. 46 ( 2 ) page: 595 - 603   2017.8

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    PurposeTo assess the performance of four-dimensional phase-contrast vastly undersampled isotropic projection reconstruction (4D PC-VIPR) at 3.0T in depicting intrarenal arteries compared with computed tomography angiography (CTA), and its correlation with arterial flowmetry in comparison with Doppler ultrasonography (DUS).
    Materials and MethodsIn our prospective single-arm study, subjects were 25 patients who underwent renal transplant-related surgery at our hospital between July 2011 and June 2015. In the morphological study, depictions of renal artery branches delineated by magnetic resonance angiography (MRA)/4D PC-VIPR without gadolinium contrast agent were compared in seven living transplant recipients with the same kidney delineated by CTA in seven living transplant donors. In the flowmetric study, flow velocities in the renal (main stem), segmental, and interlobar arteries during systole and diastole were measured in 12 recipients using noncontrast MRA/4D PC-VIPR, and were compared with those obtained from DUS.
    ResultsConcerning MRA, average confidence levels of delineation rated by six observers for secondary to third level renal artery branches were 82.9-100% and for the fourth to fifth branches were 60.8-89.7% (average kappa value of 0.588 [95% confidence interval: 0.522-0.653]). Total flow velocities measured using 4D PC-VIPR and DUS demonstrated significant correlations during both systole and diastole with acceptable bias (r=0.902; P &lt; 0.001 in systole and r=0.734; P &lt; 0.001 in diastole).
    Conclusion4D PC-VIPR was useful in generating both morphological and hemodynamic information for evaluation of transplant intrarenal arteries without the need for contrast media. Level of Evidence: 2 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:595-603

    DOI: 10.1002/jmri.25607

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  40. Validation of numerical simulation methods in aortic arch using 4D Flow MRI Reviewed

    Shohei Miyazaki, Keiichi Itatani, Toyoki Furusawa, Teruyasu Nishino, Masataka Sugiyama, Yasuo Takehara, Satoshi Yasukochi

    HEART AND VESSELS   Vol. 32 ( 8 ) page: 1032 - 1044   2017.8

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    Computational fluid dynamics (CFD) are the gold standard in studying blood flow dynamics. However, CFD results are dependent on the boundary conditions and the computation model. The purpose of this study was to validate CFD methods using comparison with actual measurements of the blood flow vector obtained with four-dimensional (4D) flow magnetic resonance imaging (MRI). 4D Flow MRI was performed on a healthy adult and a child with double-aortic arch. The aortic lumen was segmented to visualize the blood flow. The CFD analyses were performed for the same geometries based on three turbulent models: laminar, large eddy simulation (LES), and the renormalization group k-epsilon model (RNG k-epsilon). The flow-velocity vector components, namely the wall shear stress (WSS) and flow energy loss (EL), of the MRI and CFD results were compared. The flow rate of the MRI results was underestimated in small vessels, including the neck vessels. Spiral flow in the ascending aorta caused by the left ventricular twist was observed by MRI. Secondary flow distal to the aortic arch was well realized in both CFD and MRI. The average correlation coefficients of the velocity vector components of MRI and CFD for the child were the highest for the RNG k-epsilon model (0.530 in ascending aorta, 0.768 in the aortic arch, 0.584 in the descending aorta). The WSS and EL values of MRI were less than half of those of CFD, but the WSS distribution patterns were quite similar. The WSS and EL estimates were higher in RNG k-epsilon and LES than in the laminar model because of eddy viscosity. The CFD computation realized accurate flow distal to the aortic arch, and the WSS distribution was well simulated compared to actual measurement using 4D Flow MRI. However, the helical flow was not simulated in the ascending aorta. The accuracy was enhanced by using the turbulence model, and the RNG k-epsilon model showed the highest correlation with 4D Flow MRI.

    DOI: 10.1007/s00380-017-0979-2

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  41. Characterizing saccular aortic arch aneurysms from the geometry-flow dynamics relationship.

    Natsume K, Shiiya N, Takehara Y, Sugiyama M, Satoh H, Yamashita K, Washiyama N.

    J Thorac Cardiovasc Surg.   Vol. 153 ( 6 ) page: 1413-1420   2017.6

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  42. Characterizing saccular aortic arch aneurysms from the geometry-flow dynamics relationship Reviewed International journal

    Kayoko Natsume, Norihiko Shiiya, Yasuo Takehara, Masataka Sugiyama, Hiroshi Satoh, Katsushi Yamashita, Naoki Washiyama

    JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY   Vol. 153 ( 6 ) page: 1413 - 1420.e1   2017.6

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    Objective: Low wall shear stress (WSS) has been reported to be associated with accelerated atherosclerosis, aneurysm growth, or rupture. We evaluated the geometry of aortic arch aneurysms and their relationship with WSS by using the 4-dimensional flow magnetic resonance imaging to better characterize the saccular aneurysms.
    Methods: We analyzed the geometry in 100 patients using multiplanar reconstruction of computed tomography. We evaluated WSS and vortex flow using 4-dimensional flow magnetic resonance imaging in 16 of them, which were compared with 8 age-matched control subjects and eight healthy young volunteers.
    Results: Eighty-two patients had a saccular aneurysm, and 18 had a fusiform aneurysm. External diameter/aneurysm length ratio and sac depth/neck width ratio of the fusiform aneurysms were constant at 0.76 +/- 0.18 and 0.23 +/- 0.09, whereas those of saccular aneurysms, especially those involving the outer curvature, were higher and more variable. Vortex flow was always present in the aneurysms, resulting in low WSS. When the sac depth/neck width ratio was less than 0.8, peak WSS correlated inversely with luminal diameter even in the saccular aneurysms. When this ratio exceeded 0.8, which was the case only with the saccular aneurysms, such correlation no longer existed and WSS was invariably low.
    Conclusions: Fusiform aneurysms elongate as they dilate, and WSS is lower as the diameter is larger. Saccular aneurysms dilate without proportionate elongation, and they, especially those occupying the inner curvature, have higher and variable sac depth/neck width ratio. When this ratio exceeds 0.8, WSS is low regardless of diameter, which may explain their malignant clinical behavior.

    DOI: 10.1016/j.jtcvs.2016.11.032

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  43. すとらびすむす 神の創造

    竹原 康雄

    画像診断   Vol. 37 ( 7 ) page: 621 - 621   2017.5

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    Publisher:学研メディカル秀潤社  

    DOI: 10.15105/gzj.0000003167

    CiNii Research

  44. 【最新分類に基づく画像による悪性腫瘍の病期診断2017】 膵癌. Reviewed

    牛尾 貴輔, 阪原 晴海, 竹原 康雄

    臨床画像   Vol. 33 ( 4月増刊 ) page: 140-8   2017

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  45. 【圧縮センシングの旅-MRI高速化を探る-】 圧縮センシング(Cs)の現状 臨床MRIの知見と有用性. Reviewed

    寺田 理希, 松芳 圭吾, 小板橋 実夏, 安澤 千奈, 大杉 正典, 内藤 眞明, 沓掛 康道, 岩倉 岳史, 山中 典子, 吉原 和代, 吉原 修, 礒田 治夫, 竹原 康雄

    Rad Fan   Vol. 15 ( 15 ) page: 43-7   2017

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  46. 【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. Reviewed

    小川 浩, 鈴木 耕次郎, 竹原 康雄, 長縄 慎二

    胆と膵   Vol. 38 ( 11 ) page: 1255-60   2017

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  47. Validation of numerical simulation methods in aortic arch using 4D Flow MRI. Reviewed

    Miyazaki S, Itatani K, Furusawa T, Nishino T, Sugiyama M, Takehara Y, Yasukochi S.

    Heart Vessels.   Vol. 32 ( 8 ) page: 1032-1044   2017

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  48. Intra-left ventricular flow dynamics in patients with preserved and impaired left ventricular function: Analysis with 3D cine phase contrast MRI (4D-Flow). Reviewed

    Suwa K, Saitoh T, Takehara Y, Sano M, Saotome M, Urushida T, Katoh H, Satoh H, Sugiyama M, Wakayama T, Alley M, Sakahara H, Hayashi H.

    J Magn Reson Imaging.   Vol. 44 ( 6 ) page: 1493-1503   2016.12

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Books 1

  1. シンプル薬理学

    野村 隆英, 石川 直久, 梅村 和夫, 天ヶ瀬 紀久子, 野元 正弘, 岡田 尚志郎, 植田 真一郎, 近藤 一直, 松野 浩之, 西尾 眞友, 三鴨 廣繁, 丹羽 雅之, 竹原 康雄, 新井 信

    南江堂  2020  ( ISBN:9784524246588

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MISC 31

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

    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

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    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

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  2. 【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

    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

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    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)

  3. IVIMおよび灌流MRIを用いた免疫チェックポイント阻害剤投与後の腫瘍評価

    柄山 正人, 芳澤 暢子, 杉山 将隆, 森 和貴, 安井 秀樹, 井上 裕介, 穗積 宏尚, 鈴木 勇三, 古橋 一樹, 藤澤 朋幸, 榎本 紀之, 中村 祐太郎, 乾 直輝, 五島 聡, 須田 隆文, 竹原 康雄

    日本呼吸器学会誌   Vol. 10 ( 増刊 ) page: 156 - 156   2021.4

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  4. 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

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    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

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  5. 【画像診断に必要なartifactsの知識】MRIにおける注意すべきartifacts

    寺田 理希, 竹原 康雄

    臨床放射線   Vol. 65 ( 12 ) page: 1275 - 1294   2020.11

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    <文献概要>はじめに MRIでは,高度な静磁場均一性が必要とされる。また,信号の送受信や受信した信号による画像再構成には非常にデリケートなシステムが統合されている。撮影対象も様々な組織を含み,呼吸,拍動,蠕動といった生理的な動きをする生体が対象である。こうした多くの因子の複合として出来上がるMR画像では,アーチファクトから逃れられないと考えてよい。また,近年のMR装置では,パラレルイメージングや圧縮センシング(compressed sensing:CS),種々のK空間のデータ充填方法などにより高速化が可能となってきている。このため,撮像法に特有なアーチファクトが発生することも多くなっている。我々MRIに従事する医療者は,アーチファクトを認識すること,アーチファクトを防ぐ対応ができることが重要である。しかし,現実のMRIにおけるアーチファクトを画像内からまったくなくすことが難しい場合も多い。よって最適な対応として,アーチファクトを関心領域から除き,最小限にするなど様々な手法も必要となる。本稿では,基礎的なものから近年気になるアーチファクトまでを紹介し,要因・対応などについて紹介する。

    Other Link: https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2020&ichushi_jid=J01565&link_issn=&doc_id=20201125080004&doc_link_id=10.18888%2Frp.0000001434&url=https%3A%2F%2Fdoi.org%2F10.18888%2Frp.0000001434&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

  6. 拡散強調MRIにおける非小細胞肺がんのADCヒストグラムの変化と免疫チェックポイント阻害剤の有効性との関連

    柄山 正人, 芳澤 暢子, 杉山 将隆, 森 和貴, 乾 直輝, 五島 聡, 須田 隆文, 竹原 康雄

    肺癌   Vol. 60 ( 6 ) page: 636 - 636   2020.10

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  7. 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

    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

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  8. 【ウイルス肝炎アップデート】診断 肝疾患評価におけるCT・MRI NAFLD・NASHを中心として

    竹原 康雄

    診断と治療   Vol. 108 ( 2 ) page: 197 - 204   2020.2

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    <Headline>1 慢性肝障害による肝線維化と肝細胞癌の発生リスクは、概ね直線関係である。2 DAAの出現で、慢性肝障害診療の関心はウイルス性肝炎による肝線維化からNAFLD・NASHによる肝線維化に移りつつある。3 肝特異性造影剤を用いた肝細胞癌の造影MRは異型腺腫様過形成の発癌リスクを知ることができ、介入治療のタイミングをはかるのに有用である。4 CT・MRIは肝の脂肪化定量、NAFLD・NASHの肝線維化、異型腺腫様過形成、肝細胞癌という一連の病態進行を非侵襲的、縦断的、one stop shop的に評価できる画像診断法である(著者抄録)

  9. 【MRIで読み解く心臓と脈管:流れと機能】腹部大動脈瘤の4D-flow

    杉山 将隆, 竹原 康雄

    臨床画像   Vol. 36 ( 1 ) page: 42 - 48   2020.1

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    4Dーflowにより,腹部大動脈内の三次元的な血流ベクトルデータを心時相分割表示することが可能で,血流動態を視覚的かつ定量的に評価することができるようになった。腹部大動脈瘤の形成にかかわる要因の探究から,治療効果の評価などに力を発揮する可能性を秘めている。(著者抄録)

    Other Link: https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2020&ichushi_jid=J01843&link_issn=&doc_id=20200107200005&doc_link_id=10.18885%2FCI.0000000106&url=https%3A%2F%2Fdoi.org%2F10.18885%2FCI.0000000106&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

  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

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  11. 【Step up MRI 2019 最新技術の研究開発・臨床応用から展望するMRIの未来】MRIの最新技術と未来展望 臨床編 4D-Flowを用いた血流解析の臨床応用 新しい診断リテラシーの現状と普及に向けての期待

    竹原 康雄

    INNERVISION   Vol. 34 ( 9 ) page: 45 - 48   2019.8

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    最近、3社のMRIメーカーから4D-Flowが臨床現場に導入された。データの後処理のための流体解析ソフトウエアを提供するメーカーも、筆者の知るかぎり9社を数える。今や4D-Flowは、すべての診療放射線技師や放射線科医、各科臨床医が知っておくべき診断リテラシーとなりつつある。本稿では、この分野に新規参入を検討されている研究者や臨床家をターゲットに、まず4D-Flowとは何か?そして、その臨床現場における現状と将来性について簡単に論じてみたい。(著者抄録)

  12. 【MRI Evolution 2019〜「測ってなんぼ!」MRIでの定量を考える〜】4D-Flowを用いた流体解析

    竹原 康雄

    Rad Fan   Vol. 17 ( 10 ) page: 37 - 40   2019.8

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    4D-Flowは観察範囲内の全てのプロトンの速度ベクトルを遍く計測することのできる新しいMR技術である。3次元+時相分割で従来思いもよらなかった血行動態計測における乱流の問題が再認識されつつある。(著者抄録)

  13. MRIによる血流解析

    竹原 康雄

    静脈学   Vol. 30 ( 2 ) page: 102 - 102   2019.6

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  14. 【症候別画像診断プロトコル】3T MRI独特のシーケンス 自由呼吸下撮像

    小森 芳秋, 竹原 康雄

    臨床画像   Vol. 35 ( 4月増刊 ) page: 172 - 173   2019.4

  15. 【症候別画像診断プロトコル】3T MRI独特のシーケンス 3D-GraSE法によるMRCP

    天野 智康, 高橋 護, 一条 勝利, 竹原 康雄

    臨床画像   Vol. 35 ( 4月増刊 ) page: 170 - 171   2019.4

  16. 【症候別画像診断プロトコル】3T MRI独特のシーケンス 圧縮センシング

    寺田 理希, 竹原 康雄

    臨床画像   Vol. 35 ( 4月増刊 ) page: 166 - 168   2019.4

  17. 外科診療に役立つ新しいMRI診断技術

    竹原 康雄

    日本外科学会雑誌   Vol. 120 ( 1 ) page: 56 - 61   2019.1

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    MRの特徴は無被曝、低侵襲、組織特異性コントラスト、速度、拡散、弾性率、組織特異性造影剤の利用等多彩である。これらを駆使したMRI検査の外科診療への応用例を述べた。(著者抄録)

  18. 【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   2018.5

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  19. 【大動脈疾患の画像診断:画像所見・画像からみた自然史・治療効果判定】大動脈疾患のMRI

    竹原 康雄

    臨床画像   Vol. 34 ( 1 ) page: 40 - 52   2018.1

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    MRAはガドリニウムキレート造影剤による造影MRAを基本とし、ほかの組織コントラストも併用することで、種々の大動脈疾患に対し、広い適応を有する。高速化による血行動態解析は大動脈解離やステントグラフト内挿術(EVAR,TEVAR)後のエンドリーク検出にも有用である。一時期問題となった腎性全身性線維症(NSF)も、現行のガイドラインが確定してから新たな患者は出現しておらず、また、NSFを起こしにくいマクロ環造影剤の出現や、非造影MRAの進歩などもMRAの安全性を高めている。MRAは現在高速化が進行中であり、今後、さらなる適応拡大が望めると考えられる。(著者抄録)

    Other Link: https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2018&ichushi_jid=J01843&link_issn=&doc_id=20180111090004&doc_link_id=10.18885%2FJ01843.2018090581&url=https%3A%2F%2Fdoi.org%2F10.18885%2FJ01843.2018090581&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

  20. 【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

    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

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    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)

  21. 【圧縮センシングの旅-MRI高速化を探る-】圧縮センシング(CS)の現状 臨床MRIの知見と有用性

    寺田 理希, 松芳 圭吾, 小板橋 実夏, 安澤 千奈, 大杉 正典, 内藤 眞明, 沓掛 康道, 岩倉 岳史, 山中 典子, 吉原 和代, 吉原 修, 礒田 治夫, 竹原 康雄

    Rad Fan   Vol. 15 ( 15 ) page: 43 - 47   2017.11

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    圧縮センシング(Compressed Sensing:CS)は、情報理論の分野において発展した手法をMRIに適応した高速撮像法であり注目される技術である。当院では、2017年8月にGEHC社製Discovery MR750 3.0TとOptima MR450W 1.5Tの2台のMRI装置のバージョンアップに伴いCSの使用が可能となった。現状でのCSにおける臨床応用の知見と有用性について紹介する。(著者抄録)

  22. 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

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  23. MR Angiographyに関する最新技術と知見

    竹原 康雄

    脈管学   Vol. 57 ( Suppl. ) page: S94 - S95   2017.10

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  24. 腹部MRIの最前線

    竹原 康雄

    JART: 日本診療放射線技師会誌   Vol. 64 ( 9 ) page: 1059 - 1059   2017.9

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  25. 1.5T及び3.0T装置を用いた4D-Flowの精度の比較

    松本 卓弥, 天野 智康, 名倉 義和, 水野 孝一, 土屋 甲司, 高橋 護, 竹原 康雄

    日本放射線技術学会雑誌   Vol. 73 ( 9 ) page: 970 - 971   2017.9

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  26. MR用造影剤の安全性

    竹原 康雄

    日本医学放射線学会秋季臨床大会抄録集   Vol. 53回   page: S388 - S388   2017.8

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  27. 血流速度に基づいたバイオマーカーによる脳動脈瘤増大とブレブ発生の予測の検討

    石黒 健太, 礒田 治夫, 水野 崇, 田嶋 駿亮, 竹原 康雄, 寺田 理希, 小杉 崇文, 大西 有希, 福山 篤司

    日本バイオレオロジー学会誌(B&R)   Vol. 31 ( 2 ) page: 85 - 85   2017.5

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  28. 腹部大動脈瘤ステントグラフト内挿術後2型エンドリーク症例の動脈瘤分枝血管に対する4D-flow MRIを用いた血行動態学的解析

    片橋 一人, 海野 直樹, 竹原 康雄, 山本 尚人, 犬塚 和徳, 佐野 真規, 斉藤 貴明, 杉澤 良太, 矢田 達朗, 嘉山 貴文, 今野 弘之

    日本外科学会定期学術集会抄録集   Vol. 117回   page: SF - 6   2017.4

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  29. 【最新分類に基づく画像による悪性腫瘍の病期診断2017】膵癌

    牛尾 貴輔, 阪原 晴海, 竹原 康雄

    臨床画像   Vol. 33 ( 4月増刊 ) page: 140 - 148   2017.4

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    2016年に『膵癌取扱い規約』(第7版)が発行され,新たな規約では切除可能性分類が明記され国際分類との整合性が保たれる形となった。また,一部には日本独自となる分類も含まれている。本稿では,実際の症例を提示しつつ膵癌の典型像および局所進展,切除可能性分類について述べた。(著者抄録)

    Other Link: https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2017&ichushi_jid=J01843&link_issn=&doc_id=20170410300010&doc_link_id=10.18885%2FJ01843.2017206467&url=https%3A%2F%2Fdoi.org%2F10.18885%2FJ01843.2017206467&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

  30. 診断に苦慮した悪性黒色腫の1例

    兵頭 直子, 那須 初子, 廣瀬 裕子, 汪 洋, 大石 愛, 杉山 将隆, 宇佐美 諭, 伊東 洋平, 平井 雪, 芳澤 暢子, 牛尾 孝輔, 山下 修平, 神谷 実佳, 竹原 康雄, 阪原 晴海

    Japanese Journal of Radiology   Vol. 35 ( Suppl. ) page: 25 - 25   2017.2

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  31. A Sea Change in Radiology : RSNA 2016 report

      Vol. 44 ( 2 ) page: 153 - 155   2017.2

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    CiNii Books

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Works 8

  1. ジーイー横河メディカルシステム株式会社 多コイル感度エンコーディング法による超高速撮像法の実用化

    2003

  2. 日本シェーリング株式会社 新しい組織・病変特異性MR造影剤の研究

    2003

  3. 光ケミカル研究所(岡山)“金属ポルフィリンMR造影剤の開発”

  4. 東京女子医大消化器病センター(東京)“MRCPによる慢性膵炎診断能”

  5. 静岡大学工学部(浜松)“デンドリマー型MR造影剤研究”

  6. 聖隷三方原病院消化器病センター(浜松)“MRCPによる慢性膵炎診断能”

  7. 聖隷三方原病院放射線科,循環器科(浜松)“循環器MR臨床研究”

  8. 産業技術総合研究所ライフエレクトロニクス研究ラボ医用ビジョングループ(大阪)“磁気共鳴 画像法を用いた小動物の画像化の研究”

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KAKENHI (Grants-in-Aid for Scientific Research) 6

  1. 大動脈ステントグラフト術後タイプ2エンドリークに対する新規診断・治療戦略の開発

    Grant number:22K08917  2022.4 - 2025.3

    科学研究費助成事業  基盤研究(C)

    杉本 昌之, 児玉 章朗, 竹原 康雄, 坂野 比呂志, 川井 陽平

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    腹部大動脈ステントグラフト留置術(EVAR)後の「type 2 endoleak」( T2EL)は高頻度の合併症であるが治療方針のエビデンスは乏しい。4D-flow MRは血行動態という「動的」要因を非侵襲的に評価可能である。本研究はEVAR患者を対象とし、1)4D-flow MRでT2ELによる瘤内圧変化や血液流入といった「動的」因子を定量化するとともに、2)EVAR後の中~長期成績(瘤径、T2EL、再治療)を観察する。データ解析によってT2ELの病態解明とT2EL治療の最適化と長期予後改善を目指す。

  2. Development of Rupture-Risk-Prediction System for Aortic Aneurysm Using Fluid&#8211;Structure Interaction Analysis.

    Grant number:21H02868  2021.4 - 2024.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

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    Authorship:Principal investigator 

    Grant amount:\17420000 ( Direct Cost: \13400000 、 Indirect Cost:\4020000 )

  3. MR strategies to solve problems after endovascular aortic repair.

    Grant number:17K10398  2017.4 - 2020.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)  Grant-in-Aid for Scientific Research (C)

    Takehara Yasuo

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    Grant amount:\4680000 ( Direct Cost: \3600000 、 Indirect Cost:\1080000 )

    Endovascular aneurysm repair (EVAR) has become a viable alternative to conventional surgical open repair owing to its perioperative survival benefit; however, EVAR is associated with a unique complication called endoleak (EL), which continues to perfuse and pressurize the aneurysm sac and cause aneurysm enlargement and rupture.
    Type I and type III endoleak were more detectable with MR angiography and streamline analysis with 4D Flow within the aneurysm. A comprehensive analysis of concurrent multiple T2EL vessels using 4D-flow MRI may enable prediction of the sac expansion after EVAR by larger amplitude of the flow velocity in the branch arteries.

  4. 腹部大動脈瘤ステントグラフト内挿術後の諸問題解決を目指すMRIの新戦略

    2017 - 2020

    文部科学省  科学研究費補助金(基盤研究C) 

    竹原 康雄

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  5. Exploratory research for predicting fate of type 2 endoleaks after endovascular repair of abdominal aortic aneurysms

    Grant number:16K15629  2016.4 - 2019.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research  Grant-in-Aid for Challenging Exploratory Research

    Unno Naoki, Takehara Yasuo

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    We analyzed the hemodynamic features of each type II endoleak (T2EL) vessel with four-dimensional (4D)-flow magnetic resonance imaging (MRI) and comprehensively assessed multiple T2EL vessels to determine the hemodynamic parameters that can be used to predict sac shrinkage. Using the 4D-flow MRI analysis, we identified that a higher peak instantaneous flow rate and increased cumulative flow-volume rate might be associated with persistency of the T2EL vessels. A total accumulation of flow-volume per sac may predict T2ELs that cause sac expansion. A comprehensive analysis of concurrent, multiple T2EL vessels using these hemodynamic parameters may enable us to predict the fate of aneurysm sacs after endovascular aortic aneurysm repair.

  6. Shear stiffness of intracranial tumors using MRE

    Grant number:15K10359  2015.4 - 2018.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)  Grant-in-Aid for Scientific Research (C)

    Sakai Naoto

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    The degree of tumor stiffness or consisitency is critical information for precise neurosurgical resection of intracranial tumors. MR eastography(MRE) is an emarging technology enabling the noninvasive assessment of the viscoelastic properties of tissues in vitro.We evaluated the stiffness of 4 common intracranial tumors:meningiomas,pituitary adenomas,vestibular schwannoma and gliomas using MRE and tested whether MRE had the potential to discriminate firm tumors preoperatively.As the result, MRE could evaluate those intracranial tumors on the basis of their physical property of shear stiffness. MRE may be useful in the preoperative discrimination of firm tumors.

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Teaching Experience (Off-campus) 10

  1. 看護学科放射線医学講義 MRI検査(医学部看護学科3年生)(90分1コマ)

    浜松医科大学医学部看護学科)

  2. ユニット8 消化器系講義Ⅰ肝胆道の画像診断(医学部医学科4年生)90分1コマ

    浜松医科大学医学部医学科)

  3. ユニット3 腹部画像診断(医学部医学科3年生)90分1コマ

    浜松医科大学医学部医学科)

  4. ユニット3 胸部画像診断(医学部医学科3年生)90分1コマ

    浜松医科大学医学部医学科)

  5. ユニット10呼吸器外科画像診断Ⅱ(医学部医学科4年生)(90分1コマ)

    浜松医科大学医学部医学科)

  6. プライマリ・ケアの実践講 胸腹部単純X線、CT、MRIの見方(50分1コマ)

    Hamamatsu University School of Medicine)

  7. 看護学科放射線医学講義 X線検査(医学部看護学科3年生)(90分1コマ)

    浜松医科大学医学部看護学科)

  8. (1) 先端医学特論Ⅲ 病期診断・画像診断(大学院博士過程)(90分1コマ)

    浜松医科大学医学部大学院)

  9. 臨床医学入門講義 単純Ⅹ線診断(医学部医学科5年生)90分1コマ

    浜松医科大学医学部医学科)

  10. 胸部画像診断(医学部医学科6年生)(90分1コマ)

    浜松医科大学医学部医学科)

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