研究者データベース


フリーワードで探す

全文検索となっています

下平 政史シモヒラ マサシ

所属部署医学研究科放射線医学分野
職名准教授
メールアドレス
ホームページURL
生年月日
Last Updated :2020/07/02

研究者基本情報

基本情報

    科研費研究者番号:60597821

学歴

  •  - 2011年03月, 名古屋市立大学医学部大学院
  •  - 2003年03月, 名古屋市立大学, 医学部

学位

  • 名古屋市立大学大学院医学研究科放射線医学分野/博士(医学)

所属学協会

  • 日本IVR学会
  • 日本医学放射線学会
  • 日本HHT研究会
  • 日本末梢血管塞栓療法研究会
  • 日本救急放射線研究会
  • 日本外傷学会
  • 日本救急医学会
  • 日本核医学会

委員歴

  •  - 現在, 日本IVR学会, 国際委員会 委員
  •  - 現在, 日本IVR学会, 学術・教育委員会 委員

経歴

  •   2019年04月 - 現在, 名古屋市立大学大学院医学研究科, 放射線医学分野, 准教授
  •   2015年04月 - 2019年03月, 名古屋市立大学大学院医学研究科, 放射線医学分野, 講師
  •   2011年04月 - 2015年03月, 名古屋市立大学大学院医学研究科, 放射線医学分野, 助教
  •   2010年04月 - 2011年03月, 名古屋市立大学大学院医学研究科, 放射線医学分野, 臨床研究医
  •   2009年04月 - 2010年03月, 米国オレゴン健康科学大学, 放射線科, 研究員
  •   2007年07月 - 2009年03月, 名古屋市立大学大学院医学研究科, 放射線医学分野, 臨床研究医
  •   2006年04月 - 2007年06月, 成田記念病院, 放射線科, 医員
  •   2005年04月 - 2006年03月, 名古屋市立大学大学院医学研究科, 放射線医学分野, 臨床研究医
  •   2003年04月 - 2005年03月, 名古屋市立大学大学院医学研究科, 放射線医学分野, 臨床研修医
  • Research Fellow of Dotter Interventional Institute (2009.4-2010.3)

研究活動情報

研究分野

  • ライフサイエンス, 放射線科学, IVR

研究キーワード

    放射線医学, IVR

論文

  • 2D-shear wave elastography in the prediction of type II endoleaks after endovascular aneurysm repair., Bando Y, Kitase M, Shimohira M, Honda J, Furuta Y, Kasuya A, Imada H, Mizutani M, Shibamoto Y, Minimally invasive therapy & allied technologies : MITAT : official journal of the Society for Minimally Invasive Therapy, 1 - 6,   2019年10月, 査読有り
  • Bronchial arterial embolization using a gelatin sponge for hemoptysis from pulmonary aspergilloma: comparison with other pulmonary diseases., Shimohira M, Ohta K, Nagai K, Sawada Y, Nakashima M, Maki H, Bando Y, Shibamoto Y, Emergency radiology, 26, (5) 501 - 506,   2019年10月, 査読有り
  • Preoperative transcatheter arterial embolization using a gelatin sponge for head and neck tumors., Hashizume T, Shimohira M, Ohta K, Suzuki K, Sawada Y, Nakamura Y, Suzuki M, Murakami S, Shibamoto Y, Minimally invasive therapy & allied technologies : MITAT : official journal of the Society for Minimally Invasive Therapy, 28, (4) 206 - 212,   2019年08月, 査読有り
  • Combination of the double-microcatheter technique and triaxial system in coil packing for visceral and renal artery aneurysms., Goto T, Shimohira M, Ohta K, Suzuki K, Sawada Y, Shibamoto Y, Acta radiologica (Stockholm, Sweden : 1987), 60, (8) 1057 - 1062,   2019年08月, 査読有り
  • Advanced monoenergetic reconstruction technique in dual-energy computed tomography for evaluation of vascular anatomy before adrenal vein sampling., Nakayama K, Shimohira M, Nakagawa M, Ozawa Y, Sawada Y, Ohta K, Ohashi K, Shibamoto Y, Acta radiologica (Stockholm, Sweden : 1987),   2019年07月, 査読有り
  • Identification of the feeding arteries of hepatocellular carcinomas by performing dual arterial phase CT during pre-transarterial chemoembolization angiography., Ohta K, Shimohira M, Hashizume T, Suzuki K, Sawada Y, Shibamoto Y, Abdominal radiology (New York), 44, (6) 2276 - 2282,   2019年06月, 査読有り
  • A successful case of percutaneous fistula closure in a patient with high output heart failure and extracardiac arteriovenous fistula., Kato Y, Nakayama T, Yamamoto J, Muto K, Kitada S, Suzuki K, Shimohira M, Kamiya S, Suda H, Ohte N, Journal of cardiology cases, 19, (4) 125 - 128,   2019年04月, 査読有り
  • Use of a steerable triaxial system for challenging catheterization., Shimohira M, Nagai K, Ohta K, Sawada Y, Muto M, Hashizume T, Shibamoto Y, Minimally invasive therapy & allied technologies : MITAT : official journal of the Society for Minimally Invasive Therapy, 1 - 6,   2019年04月, 査読有り
  • The Key for Preventing Recanalization May be High Packing Density: Reply to Rajagopal et al., Shimohira M, Kawai T, Shibamoto Y, Cardiovascular and interventional radiology, 42, (2) ,   2019年02月, 査読有り
  • Hemoptysis due to Pulmonary Arteriovenous Malformation after Coil Embolization during Long-Term Follow-Up., Shimohira M, Iwata K, Ohta K, Sawada Y, Hashimoto T, Okuda K, Nakanishi R, Shibamoto Y, Case reports in radiology, 2019,   2019年, 査読有り
  • In Reply., Nakagawa M, Ozawa Y, Shimohira M, Shibamoto Y, Japanese journal of radiology, 36, (12) ,   2018年12月, 査読有り
  • Usefulness of Hydrogel-Coated Coils in Embolization of Pulmonary Arteriovenous Malformations., Shimohira M, Kawai T, Hashizume T, Muto M, Kitase M, Shibamoto Y, Cardiovascular and interventional radiology, 41, (6) 848 - 855,   2018年06月, 査読有り
  • Fibrin sheath of a peripherally inserted central catheter undepicted with gray-scale (real-time B-mode) ultrasonography: A case report., Mogi N, Nakagawa M, Matsumae H, Hattori A, Shimohira M, Shibamoto Y, Radiology case reports, 13, (3) 537 - 541,   2018年06月, 査読有り
  • Simultaneous transarterial and transvenous coil embolization for a large aneurysmal-type renal arteriovenous fistula., Nakayama K, Shimohira M, Ohta K, Suzuki K, Goto T, Sawada Y, Shibamoto Y, Radiology case reports, 13, (2) 507 - 509,   2018年04月, 査読有り
  • Investigation of an appropriate contrast-enhanced CT protocol for young patients following the Fontan operation., Nakagawa M, Ozawa Y, Nomura N, Inukai S, Shiba A, Sakurai K, Shimohira M, Shibamoto Y, Japanese journal of radiology, 36, (3) 215 - 222,   2018年03月, 査読有り
  • Unilateral pulmonary artery pre-operative occlusion test: technical feasibility and safety prior to pneumonectomy or pleuropneumonectomy for malignancy., Shimohira M, Hashizume T, Ohta K, Suzuki K, Nakagawa M, Ozawa Y, Okuda K, Moriyama S, Nakanishi R, Shibamoto Y, The British journal of radiology, 91, (1083) ,   2018年02月, 査読有り
  • Newly developed triaxial microcatheter for complicated interventions., Shimohira M, Ohta K, Suzuki K, Goto T, Sawada Y, Shibamoto Y, Minimally invasive therapy & allied technologies : MITAT : official journal of the Society for Minimally Invasive Therapy, 27, (1) 11 - 16,   2018年02月, 査読有り
  • New technique of percutaneous CT fluoroscopy-guided marking before video-assisted thoracoscopic surgery for small lung lesions: feasibility of using a 25-gauge needle without local anaesthesia., Shimamura Y, Sasaki S, Shimohira M, Ogino H, Yuki D, Nakamae K, Hara M, Shibamoto Y, The British journal of radiology, 91, (1083) ,   2018年02月, 査読有り
  • Comparison of conservative treatment versus transcatheter arterial embolisation for the treatment of spontaneously ruptured hepatocellular carcinoma., Shinmura K, Choi YH, Shimohira M, Baba Y, Ikeda S, Hayashi S, Shibamoto Y, Koriyama C, Yoshiura T, Polish journal of radiology, 83, e311 - e318,   2018年, 査読有り
  • Time-resolved magnetic resonance angiography as a follow-up method for visceral artery aneurysm treated with coil-embolisation., Tatsuya Kawai, Masashi Shimohira, Kazushi Suzuki, Kengo Ohta, Kenichiro Kurosaka, Takuya Hashizume, Hiroko Nishikawa, Masahiro Muto, Nobuyuki Arai, Hirohito Kan, Yuta Shibamoto, Polish journal of radiology, 83, e137-e142 - e142,   2018年, 査読有り, Purpose: The purpose of this study is to assess the feasibility and usefulness of time-resolved magnetic resonance angiography (TR-MRA) for follow-up of visceral artery aneurysms (VAAs) after embolotherapy. Material and methods: Twenty-one VAAs (11 splenic, six renal, three internal iliac, and one superior pancreaticoduodenal artery aneurysms) in 18 patients (median age, 64 years; range, 36-88 years) previously treated by embolisation with platinum coils, were evaluated. The mean size of the aneurysm was 10.5 cm3 (range, 0.3-132 cm3). Among them, 19 lesions were treated by aneurysmal packing with or without distal-to-proximal embolisation. For the remaining two lesions, distal-to-proximal embolization alone was performed. The mean observation period after embolotherapy was 35 weeks (range, 4-216). All patients underwent TR-MRA following an intravenous bolus injection of gadolinium chelate. Recanalisation was diagnosed when any portion of the aneurysmal sac was enhanced in the arterial phase. Results: On TR-MRA, two lesions were diagnosed as recanalised. They were confirmed by transcatheter arteriography and re-treated by embolotherapy. For the remaining 19 lesions, there were no findings of recanalisation on TR-MRA. Conclusions: TR-MRA appears to be a feasible method for follow-up examination of VAAs treated by embolotherapy.
  • Transcatheter Arterial Embolization for Renal Angiomyolipoma Using a Micro-balloon Catheter and a Mixture of Ethanol and Lipiodol, Yusuke Sawada, Masashi Shimohira, Takuya Hashizume, Ryoji Sobue, Soichiro Mori, Motoo Nakagawa, Yoshiyuki Ozawa, Taku Naiki, Takashi Nagai, Takahiro Yasui, Yuta Shibamoto, CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY, 40, (12) 1933 - 1939,   2017年12月, 査読有り, To evaluate the efficacy and safety of transcatheter arterial embolization (TAE) for renal angiomyolipoma (AML) using a micro-balloon catheter and a mixture of ethanol and lipiodol. Twelve consecutive patients with 15 AMLs, 9 females and 3 males, with a median age of 44 years (range, 11-81), underwent this procedure between 2011 and 2016. In all procedures, a micro-balloon catheter was advanced to the feeding artery of the AML and TAE was performed with a mixture of ethanol and lipiodol under balloon inflation. We reviewed medical records and images, and evaluated the technical success rate, clinical success rate, and complications. Technical success was defined as completion of TAE using the micro-balloon catheter and the mixture of ethanol and lipiodol. Clinical success was defined as reduction of tumor size on CT, which was performed before and after TAE. In 14 of 15 AMLs, the micro-balloon catheter could be advanced to the feeding artery, and TAE was performed successfully. Thus, the technical success rate was 93%. Among these 14 AMLs of 11 patients, 13 AMLs of 10 patients could be followed and tumor shrinkage was confirmed in all. Thus, the clinical success rate was 100%. Four patients had mild symptoms after TAE; the minor complication rate was 33% (4/12), and the major complication rate was 0%. TAE for renal AML using the micro-balloon catheter and mixture of ethanol and lipiodol appears to be effective and safe.
  • Calcifying aponeurotic fibroma in a girl: MRI findings and their chronological changes., Sekiguchi T, Nakagawa M, Miwa S, Shiba A, Ozawa Y, Shimohira M, Sakurai K, Shibamoto Y, Radiology case reports, 12, (3) 620 - 623,   2017年09月, 査読有り
  • Dinosaur Tail Sign: A Useful Spinal MRI Finding Indicative of Cerebrospinal Fluid Leakage, Keita Sakurai, Masafumi Kanoto, Motoo Nakagawa, Masashi Shimohira, Aya M. Tokumaru, Masashi Kameyama, Keigo Shimoji, Satoru Morimoto, Noriyuki Matsukawa, Minoru Nishio, Yuta Shibamoto, HEADACHE, 57, (6) 917 - 925,   2017年06月, 査読有り, ObjectiveTo evaluate the imaging characteristics and diagnostic utility of the Dinosaur tail sign in the diagnosis of cerebrospinal fluid (CSF) leakage. BackgroundThe authors propose the Dinosaur tail sign, defined as a combination of the dorsal epidural hyperintensities, fat tissue, spinal cord, and cauda equine on lumbosacral sagittal fat-suppressed T2-weighted image (FST2WI), as a sensitive indicator for diagnosing CSF leakage. MethodsImaging characteristics of the Dinosaur tail sign was evaluated in seven spontaneous intracranial hypotension (SIH) and 23 iatrogenic CSF leakage (ICSFL) patients. Additionally, the diagnostic index was compared between the Dinosaur tail sign and other previously reported useful magnetic resonance imaging (MRI) and magnetic resonance myelography (MRM) findings. ResultsIn contrast to other imaging findings including the epidural expansion, floating dural sac sign, and distension of the spinal epidural veins on MRI, and paraspinal fluid collections (PFC) on MRM, the Dinosaur tail sign was found equally in both SIH and ICSFL patients (6 SIH and 19 ICSFL; 83% of all patients with CSF leakage). The Dinosaur tail sign showed sufficient diagnostic utility (sensitivity 83%, specificity 94%, accuracy 89%) that was comparable to that of PFC. ConclusionThe Dinosaur tail sign is a useful imaging finding suggestive of CSF leakage. Evaluation of subtle interspinous arched hyperintensities on spinal MRI is mandatory for the diagnosis of SIH and ICSFL.
  • Beyond the midbrain atrophy: wide spectrum of structural MRI finding in cases of pathologically proven progressive supranuclear palsy, Keita Sakurai, Aya M. Tokumaru, Keigo Shimoji, Shigeo Murayama, Kazutomi Kanemaru, Satoru Morimoto, Ikuko Aiba, Motoo Nakagawa, Yoshiyuki Ozawa, Masashi Shimohira, Noriyuki Matsukawa, Yoshio Hashizume, Yuta Shibamoto, NEURORADIOLOGY, 59, (5) 431 - 443,   2017年05月, 査読有り, Purpose Recently, it has been recognized that pathologically proven progressive supranuclear palsy (PSP) cases are classified into various clinical subtypes with non-uniform symptoms and imaging findings. This article reviews essential imaging findings, general information, and advanced magnetic resonance imaging (MRI) techniques for PSP and presents these MRI findings of pathologically proven typical and atypical PSP cases for educational purposes. Methods With the review of literatures, notably including atypical pathologically proven PSP cases, MRI and clinical information of 15 pathologically proven typical and atypical PSP cases were retrospectively evaluated. Results In addition to typical symptoms, PSP patients can exhibit atypical symptoms including levodopa-responsive parkinsonism, pure akinesia, non-fluent aphasia, corticobasal syndrome, and predominant cerebellar ataxia. As well as clinical symptoms, the degree of midbrain atrophy, a well-known imaging hallmark, is not consistent in atypical PSP cases. This fact has important implications for the limitation of midbrain atrophy as a diagnostic imaging biomarker of PSP pathology. Additional evaluation of other imaging findings including various regional atrophies of the globus pallidus, frontal lobe, cerebral peduncle, and superior cerebellar peduncle is essential for the diagnosis of atypical PSP cases. Conculsion It is necessary for radiologists to recognize the wide clinical and radiological spectra of typical and atypical PSP cases.
  • Transcatheter Arterial Embolization for Hepatic Arterial Injury Related to Percutaneous Transhepatic Portal Intervention, Masashi Shimohira, Takuya Hashizume, Shigeru Sasaki, Kengo Ohta, Kazushi Suzuki, Motoo Nakagawa, Yoshiyuki Ozawa, Keita Sakurai, Hiroko Nishikawa, Masaki Hara, Yuta Shibamoto, CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY, 40, (2) 291 - 295,   2017年02月, 査読有り, To assess the usefulness of transcatheter arterial embolization (TAE) for the hepatic arterial injury related to percutaneous transhepatic portal intervention (PTPI). Fifty-four patients, 32 males and 22 females with a median age of 68 years (range 43-82 years), underwent PTPI. The procedures consisted of 33 percutaneous transhepatic portal vein embolizations, 19 percutaneous transhepatic variceal embolizations, and 2 percutaneous transhepatic portal venous stent placements. Two patients with gastric varices underwent percutaneous transhepatic variceal embolization twice because of recurrence. Therefore, the total number of procedures was 56. Among them, hepatic arterial injury occurred in 6 PTPIs in 5 patients, and TAE was performed. We assessed technical success, complications related to TAE, and clinical outcome. Technical success was defined as the disappearance of findings due to hepatic arterial injury on digital subtraction angiography. As hepatic arterial injuries, 4 extravasations and 2 arterioportal shunts developed. All TAEs were performed successfully. The technical success rate was 100 %. Complication of TAE occurred in 5 of 6 TAEs; 3 were focal liver infarction, not requiring further treatment, and 2 were biloma that required percutaneous drainage. Five TAEs in 4 patients were performed immediately after the PTPI, and these 4 patients were alive. However, one TAE was performed 10 h later, and the patient died due to multiple organ failure 2 months later although TAE was successful. TAE is a useful treatment for hepatic arterial injury related to PTPI. However, it should be performed at an early stage.
  • Volume of Interest Analysis of Spatially Normalized PRESTO Imaging to Differentiate between Parkinson Disease and Atypical Parkinsonian Syndrome, Keita Sakurai, Etsuko Imabayashi, Aya M. Tokumaru, Kimiteru Ito, Keigo Shimoji, Motoo Nakagawa, Yoshiyuki Ozawa, Masashi Shimohira, Masaki Ogawa, Satoru Morimoto, Ikuko Aiba, Noriyuki Matsukawa, Yuta Shibamoto, MAGNETIC RESONANCE IN MEDICAL SCIENCES, 16, (1) 16 - 22,   2017年, 査読有り, Purpose: Various magnetic resonance imaging (MRI) techniques including T2*-weighted imaging, susceptibility -weighted imaging, and MR relaxometry had been performed to evaluate different patterns of brain iron depositions in Parkinsonian syndrome. The aim of the present study was to evaluate the diagnostic value of a volume of interest (VOI) analysis on the principles of echo shifting with a train of observations (PRESTO) imaging using the statistical parametric mapping (SPM) 8 and the WFU PickAtlas program for the diagnosis of Parkinsonian syndrome. Methods: Fifty subjects, including 13 with the Parkinsonian variant of multiple system atrophy (MSA-P), 12 with progressive supranuclear palsy (PSP), 12 with Parkinson's disease (PD) and 13 controls were evaluated in this study. After the spatial normalization of PRESTO images on SPM8, the WFU PickAtlas program was performed to create target VOIs in the putamen, red nucleus, substantia nigra, subthalamic nucleus, and dentate nucleus. The signal intensity ratio (SIR) was calculated by normalizing the signal of each VOI to that of the cerebrospinal fluid space. These SIRs were used as determinants in receiver operating characteristic (ROC) analyses. Results: SIR of the putamen was significantly lower in MSA-P than in PSP (P = 0.0051) and controls (P = 0.0004). In contrast, SIR of the red nucleus was significantly lower in PSP than in MSA-P (P = 0.0003), PD (P = 0.0029), and controls (P = 0.0011). In ROC analyses, SIR of the putamen exhibited the highest areas under the curves (AUCs) of 0.83 (vs. PSP) and 0.91 (vs. controls) in the diagnosis of MSA-P. On the other hand, SIR of the red nucleus exhibited the highest AUCs of 0.87 (vs. MSA-P), 0.90 (vs. PD), and 0.89 (vs. controls) in the diagnosis of PSP. Conclusions: The VOI analysis based on spatially normalized PRESTO images may be useful for depicting hypointensity, indicative of abnormal iron depositions, of the putamen and red nucleus in the diagnosis of MSA-P and PSP.
  • Associations between computed tomography features of thymomas and their pathological classification, Yoshiyuki Ozawa, Masaki Hara, Masashi Shimohira, Keita Sakurai, Motoo Nakagawa, Yuta Shibamoto, ACTA RADIOLOGICA, 57, (11) 1318 - 1325,   2016年11月, 査読有り, Background Thymoma exhibits a range of histological and biological features and their imaging findings varies. Purpose To evaluate the associations between CT findings of thymomas and their classification according to the Masaoka staging system and World Health Organization (WHO) classification. Material and Methods Eighty-four patients with thymoma were evaluated. Comparisons between the CT findings of Masaoka stage I/II and III/IV lesions, and the WHO type A-B1 (low risk) and B2/B3 (high risk) lesions were performed. Results Stage III/IV thymomas (mean size, 60mm) were significantly larger than stage I/II (45mm) lesions and had more irregular shape and contour. Necrosis and calcification were observed in 16 (59%) and nine (33%) stage III/IV thymomas, and 16 (28%) and seven (12%) stage I/II lesions, respectively. Regarding the WHO classification, the high-risk thymomas displayed irregular shape and contour more often than low-risk lesions. There were significant differences between the patterns of mediastinal invasion seen in high- and low-risk groups; 21 (68%) vs. six (12%) lesions demonstrated mediastinal fat invasion, seven (23%) vs. two (4%) lesions exhibited great vessel invasion, five (16%) vs. 0 (0%) lesions displayed pericardial invasion, and 18 (58%) vs. 10 (20%) lesions invaded the lungs, respectively. Conclusion Masaoka stage III/IV thymomas were larger in size, had more irregular shape and contour, and exhibited necrosis and calcification more often than the stage I/II lesions. In the WHO classification, high-risk thymomas demonstrated more irregular shape and contour than low-risk thymomas.
  • The Role of Time-Resolved MRA for Post-treatment Assessment of Pulmonary Arteriovenous Malformations: A Pictorial Essay, Tatsuya Kawai, Masashi Shimohira, Kengo Ohta, Takuya Hashizume, Masahiro Muto, Kazushi Suzuki, Kenichiro Kurosaka, Yuta Shibamoto, CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY, 39, (7) 965 - 972,   2016年07月, 査読有り
  • Preoperative transarterial embolization using gelatin sponge for hypervascular bone and soft tissue tumors in the pelvis or extremities, Masashi Shimohira, Keiichi Nagai, Takuya Hashizume, Motoo Nakagawa, Yoshiyuki Ozawa, Keita Sakurai, Yasushi Matsushita, Satoshi Yamada, Takanobu Otsuka, Yuta Shibamoto, ACTA RADIOLOGICA, 57, (4) 457 - 462,   2016年04月, 査読有り, Background Preoperative transcatheter arterial embolization for hypervascular bone and soft tissue tumors plays an important role in reducing intraoperative blood loss (IBL). Purpose To evaluate the use of a gelatin sponge in preoperative transcatheter arterial embolization for hypervascular bone and soft tissue tumors in the pelvis or extremities. Material and Methods Thirty-seven patients (21 men, 16 women; median age, 61 years; age range, 23-79 years) underwent preoperative transcatheter arterial embolization between April 2004 and January 2015. Medical records and images were reviewed, and the technical success rate, clinical success rate, and complications were evaluated. Technical success was defined as a devascularization rate of 75% or higher, and clinical success was defined as intraoperative blood loss (IBL) <1500mL in cases undergoing surgery within 3 days of transarterial embolization and <3000mL in cases operated 4 or more days later. Results Tumor sizes were in the range of 2.0-13.0cm (median, 5.0cm). The devascularization rate was decreased by >75% at follow-up angiography in all cases, and the technical success rate was 100 % (37/37). The median IBL was 491mL (range, 30-3800mL), and the clinical success rate was 89% (33/37). The minor complication of local pain was observed in 13 out of 37 cases (35%) during or after embolization, but was controllable by an analgesic. Conclusion Preoperative transarterial embolization using a gelatin sponge appears to be feasible and safe, and may contribute to decreasing IBL.
  • Utility of dual source CT with ECG-triggered high-pitch spiral acquisition (Flash Spiral Cardio mode) to evaluate morphological features of ventricles in children with complex congenital heart defects, Motoo Nakagawa, Yoshiyuki Ozawa, Norikazu Nomura, Sachiko Inukai, Satoshi Tsubokura, Keita Sakurai, Masashi Shimohira, Masaki Ogawa, Yuta Shibamoto, JAPANESE JOURNAL OF RADIOLOGY, 34, (4) 284 - 291,   2016年04月, 査読有り, We evaluated the ability of dual source CT (DSCT) with ECG-triggered high-pitch spiral acquisition (Flash Spiral Cardio mode) to depict the morphological features of ventricles in pediatric patients with congenital heart defects (CHD). Between July 2013 and April 2015, 78 pediatric patients with CHD (median age 4 months) were examined using DSCT with the Flash Spiral Cardio mode. The types of ventricular abnormalities were ventricular septal defect (VSD) in 42 (the malaligned type in 11, perimembranous type in 23, supracristal type in 2, atrioventricular type in 2, and muscular type in 4), single ventricle (SV) in 11, and congenital corrected transposition of the great arteries (ccTGA) in 4. We evaluated the accuracy of the diagnosis of the VSD type. In cases of SV and ccTGA, we assessed the detectability of the anatomical features of both ventricles for a diagnosis of ventricular situs. DSCT confirmed the diagnoses for all VSDs. The type of defect was precisely diagnosed for all patients. The anatomical features of both ventricles were also depicted and ventricular situs of SV and ccTGA was correctly diagnosed. The results suggest that DSCT has the ability to clearly depict the configuration of ventricles.
  • Percutaneous fiducial marker placement prior to stereotactic body radiotherapy for malignant liver tumors: an initial experience, Kengo Ohta, Masashi Shimohira, Taro Murai, Junichi Nishimura, Hiromitsu Iwata, Hiroyuki Ogino, Takuya Hashizume, Yuta Shibamoto, JOURNAL OF RADIATION RESEARCH, 57, (2) 174 - 177,   2016年03月, 査読有り, The aim of this study was to describe our initial experience with a gold flexible linear fiducial marker and to evaluate the safety and technical and clinical efficacy of stereotactic body radiotherapy using this marker for malignant liver tumors. Between July 2012 and February 2015, 18 patients underwent percutaneous fiducial marker placement before stereotactic body radiotherapy for malignant liver tumors. We evaluated the technical and clinical success rates of the procedure and the associated complications. Technical success was defined as successful placement of the fiducial marker at the target site, and clinical success was defined as the completion of stereotactic body radiotherapy without the marker dropping out of position. All 18 fiducial markers were placed successfully, so the technical success rate was 100% (18/18). All 18 patients were able to undergo stereotactic body radiotherapy without marker migration. Thus, the clinical success rate was 100% (18/18). Slight pneumothorax occurred as a minor complication in one case. No major complications such as coil migration or bleeding were observed. The examined percutaneous fiducial marker was safely placed in the liver and appeared to be useful for stereotactic body radiotherapy for malignant liver tumors.
  • Visualization of the Spinal Artery by CT During Embolization for Pulmonary Artery Pseudoaneurysm., Maki H, Shimohira M, Hashizume T, Kawai T, Nakagawa M, Ozawa Y, Sakurai K, Shibamoto Y, Polish journal of radiology, 81, 382 - 385,   2016年, 査読有り
  • Transarterial Fiducial Marker Placement for Image-guided Proton Therapy for Malignant Liver Tumors, Kengo Ohta, Masashi Shimohira, Shigeru Sasaki, Hiromitsu Iwata, Hiroko Nishikawa, Hiroyuki Ogino, Masaki Hara, Takuya Hashizume, Yuta Shibamoto, CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY, 38, (5) 1288 - 1293,   2015年10月, 査読有り, The aim of this study is to analyze the technical and clinical success rates and safety of transarterial fiducial marker placement for image-guided proton therapy for malignant liver tumors. Fifty-five patients underwent this procedure as an interventional treatment. Five patients had 2 tumors, and 4 tumors required 2 markers each, so the total number of procedures was 64. The 60 tumors consisted of 46 hepatocellular carcinomas and 14 liver metastases. Five-mm-long straight microcoils of 0.018 inches in diameter were used as fiducial markers and placed in appropriate positions for each tumor. We assessed the technical and clinical success rates of transarterial fiducial marker placement, as well as the complications associated with it. Technical success was defined as the successful delivery and placement of the fiducial coil, and clinical success was defined as the completion of proton therapy. All 64 fiducial coils were successfully installed, so the technical success rate was 100 % (64/64). Fifty-four patients underwent proton therapy without coil migration. In one patient, proton therapy was not performed because of obstructive jaundice due to bile duct invasion by hepatocellular carcinoma. Thus, the clinical success rate was 98 % (54/55). Slight bleeding was observed in one case, but it was stopped immediately and then observed. None of the patients developed hepatic infarctions due to fiducial marker migration. Transarterial fiducial marker placement appears to be a useful and safe procedure for proton therapy for malignant liver tumors.
  • Image quality at low tube voltage (70 kV) and sinogram-affirmed iterative reconstruction for computed tomography in infants with congenital heart disease, Motoo Nakagawa, Yoshiyuki Ozawa, Keita Sakurai, Masashi Shimohira, Kazuya Ohashi, Miki Asano, Sachiko Yamaguchi, Yuta Shibamoto, PEDIATRIC RADIOLOGY, 45, (10) 1472 - 1479,   2015年09月, 査読有り, Lower tube voltage has advantages for CT angiography, such as improved contrast To evaluate the image quality of low-voltage (70 kV) CT for congenital heart disease and the ability of sinogram-affirmed iterative reconstruction to improve image quality. Forty-six children with congenital heart disease (median age: 109 days) were examined using dual-source CT. Scans were performed at 80 kV and 70 kV in 21 and 25 children, respectively. A nonionic iodinated contrast medium (300 mg I/ml) was used for the 80-kV protocol. The contrast medium was diluted to 75% (225 mgI/mL) with saline for the 70-kV protocol. Image noise was measured in the two protocols for each group by extracting the standard deviations of a region of interest placed on the descending aorta. We then determined whether sinogram-affirmed iterative reconstruction reduced the image noise at 70 kV. There was more noise at 70 kV than at 80 kV (29 +/- 12 vs 20 +/- 4.8; P < 0.01). Sinogram-affirmed iterative reconstruction with grade 4 strength settings improved the noise (20 +/- 5.9; P < 0.01) for the 70-kV group. Sinogram-affirmed iterative reconstruction improved the image quality of CT in congenital heart disease.
  • Hepatic arterial infusion chemotherapy with fine-powder cisplatin and iodized-oil suspension in patients with intermediate-stage and advanced-stage (Barcelona Clinic Liver Cancer stage-B or stage-C) hepatocellular carcinoma: multicenter phase-II clinical study, Haruyuki Takaki, Koichiro Yamakado, Masakatsu Tsurusaki, Taku Yasumoto, Yasutaka Baba, Yoshiaki Narimatsu, Masashi Shimohira, Masato Yamaguchi, Kunihiro Matsuo, Yoshitaka Inaba, Koji Mikami, Ryohei Watanabe, Norifumi Nishida, Hiroshi Anai, Hideaki Kakizawa, Shozo Hirota, INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY, 20, (4) 745 - 754,   2015年08月, 査読有り, Purpose This single-arm, multicenter, phase-II trial evaluated the efficacy and safety of hepatic arterial infusion chemotherapy (HAIC) using fine-powder cisplatin and iodized-oil suspension in patients with intermediate- and advanced-stage [Barcelona Clinic Liver Cancer (BCLC) stage-B and stage-C] hepatocellular carcinomas (HCCs). Methods The Institutional Review Board approved this study and patients provided written informed consent. Thirty-five patients (24 men and 11 women, mean 74 +/- 6 years [range 60-87 years]) with BCLC stage-B (57 %, 20/35) or stage-C (43 %, 15/35) HCCs who were not candidates for other locoregional treatments were enrolled. HAIC was performed using a suspension of fine-powder cisplatin with a maximum dose of 65 mg/m(2) and iodized oil on demand. The primary endpoint was the response rate evaluated based on Response Evaluation Criteria in Solid Tumor (RECIST) and modified RECIST (mRECIST). Secondary endpoints were overall survival, progression-free survival, and safety. Results The initial and best overall response rates at 4 weeks and 3 months, respectively, were 14 and 17 % based on RECIST, and 57 and 23 % based on mRECIST. The median overall and progression-free survival times were 18 and 4 months, respectively. The most frequent grade-3 or grade-4 adverse events were elevation of serum alanine (23 %) and aspartate aminotransferase (20 %), and thrombocytopenia (17 %). Conclusion This HAIC provides promising therapeutic effects with acceptable safety to patients with intermediate-stage and advanced-stage HCCs.
  • Reperfusion Rates of Pulmonary Arteriovenous Malformations after Coil Embolization: Evaluation with Time-Resolved MR Angiography or Pulmonary Angiography, Masashi Shimohira, Tatsuya Kawai, Takuya Hashizume, Kengo Ohta, Motoo Nakagawa, Yoshiyuki Ozawa, Keita Sakurai, Yuta Shibamoto, JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY, 26, (6) 856 - 864,   2015年06月, 査読有り, Purpose: To assess reperfusion rates after coil embolization for pulmonary arteriovenous malformations (PAVMs) using time-resolved magnetic resonance (MR) angiography or pulmonary angiography. Materials and Methods: Patients with PAVMs who underwent embolization and met the following inclusion criteria were included: (a) embolization was performed using bare or fibered platinum microcoils or both, (b) the complete cessation of flow was confirmed by digital subtraction angiography, and (c) follow-up examinations were conducted with time-resolved MR angiography or pulmonary angiography. Coil embolization was performed in 16 patients with 24 untreated or reperfused PAVMs. Sac embolization was performed for 12 untreated PAVMs. Feeding artery embolization was performed as primary embolization in each of the 12 reperfused PAVMs. Five PAVMs were treated 2 to 4 times because of reperfusion. The study included 32 coil embolizations. Follow-up images were reviewed, and reperfusion rates were assessed. The relationships between reperfusion and the location of PAVM, size of PAVM (feeding artery and venous sac), coils (number and total length), timing of embolization (primary or repeat embolization), and types of coils used (with or without fibered coils) were examined. Results: Reperfusion rates at 3, 6, 12, and 24 months were 8%, 27%, 36%, and 49%, respectively, for the 12 untreated PAVMs (primary embolization) and 50%, 50%, 92%, and 100%, respectively, for the 12 reperfused PAVMs (repeat embolization) (P =.0062). No significant differences were observed in the other parameters measured. Conclusions: When evaluated with time-resolved MR angiography or pulmonary angiography, reperfusion rates after coil embolization for PAVM were considerably high, particularly with repeat embolization.
  • Triaxial transarterial embolization for lower gastrointestinal bleeding: A retrospective case series, Masashi Shimohira, Takuya Hashizume, Kengo Ohta, Junichi Honda, Yuta Shibamoto, MINIMALLY INVASIVE THERAPY & ALLIED TECHNOLOGIES, 24, (2) 119 - 122,   2015年04月, 査読有り, Objective: Superselective transcatheter arterial embolization (TAE) is important for lower gastrointestinal (GI) bleeding. A new 1.9-Fr. no-taper microcatheter has recently become available and can be inserted into a 2.7-Fr. microcatheter. We assessed the applicability of this new triple co-axial (triaxial) system to TAE for lower GI bleeding. Material and methods: Five patients with lower GI bleeding underwent TAE with the triaxial system. The approach was via the femoral artery with a 4-Fr. sheath in all cases. The 4-Fr. catheter and triaxial system were inserted into the artery in which extravasation had occurred. Coil embolization was performed with 0.010-inch coils. We evaluated technical success rate, clinical success rate and complications. Results: All five cases of bleeding occurred at the ascending colon, and were caused by diverticulosis in four cases, and an injury to the artery during polypectomy in one case. The 1.9-Fr. no-taper microcatheter could be inserted into the site of extravasation, the vasa recta, in all procedures and TAE was performed successfully. The disappearance of extravasation was confirmed in all cases following TAE. No patients exhibited any signs of recurrent bleeding or complication. Conclusion: The triaxial system appears to be effective and useful in superselective TAE for lower GI bleeding.
  • Triaxial coil embolization using Guglielmi detachable coils with the voltage-dependent coil-detaching technique, Masashi Shimohira, Takuya Hashizume, Kengo Ohta, Kazushi Suzuki, Kenichiro Kurosaka, Masahiro Muto, Yuta Shibamoto, ACTA RADIOLOGICA, 56, (1) 51 - 55,   2015年01月, 査読有り, Background: A triple co-axial (triaxial) system, consisting of a 1.9-Fr non-tapered microcatheter with one marker, a 2.7-Fr microcatheter, and a 4-Fr catheter, has been recently developed, and can be used in coil embolizations using 0.010-inch Guglielmi detachable coils (GDCs) with a voltage-dependent coil-detaching technique. Purpose: To describe this new technique and evaluate its technical feasibility and clinical efficacy. Material and Methods: Twenty patients underwent this procedure. Diseases were gastrointestinal bleeding in five patients, traumatic bleeding in three patients, and other diseases in 12 patients. The technical success rate, clinical success rate, and complications of this procedure were evaluated. Technical success was defined as the successful delivery and detachment of a GDC, and clinical success was defined as the immediate postembolic complete cessation of blood flow confirmed by digital subtraction angiography. Results: A total of 140 GDCs were used and 20 arteries were embolized. The technical success rate was 94% (131/140) and clinical success rate was 95% (19/20). No major complications were reported. Conclusion: The triaxial system in coil embolization using a GDC by monitoring the voltage for coil-detaching appeared to be safe and effective.
  • Triaxial system in re-embolization for recanalization of pulmonary arteriovenous malformations., Shimohira M, Hashizume T, Kawai T, Muto M, Ohta K, Suzuki K, Shibamoto Y, Polish journal of radiology, 80, 67 - 71,   2015年, 査読有り
  • Stent Placement for Acute Superior Mesenteric Artery Occlusion Associated with Type B Aortic Dissection., Suzuki K, Shimohira M, Hashizume T, Shibamoto Y, Case reports in vascular medicine, 2015,   2015年, 査読有り
  • Triaxial system in bronchial arterial embolization for haemoptysis using N-butyl-2-cyanoacrylate, Masashi Shimohira, Takeshi Hashimoto, Saori Abematsu, Takuya Hashizume, Motoo Nakagawa, Yoshiyuki Ozawa, Keita Sakurai, Yuta Shibamoto, BRITISH JOURNAL OF RADIOLOGY, 88, (1056) ,   2015年, 査読有り, Objective: The application of bronchial artery embolization (BAE) using N-butyl-2-cyanoacrylate (NBCA) for haemoptysis was recently reported to be useful. A triple co-axial (triaxial) system consisting of a 4-Fr catheter, 2.7-Fr microcatheter and 1.9-Fr no-taper microcatheter has been developed. The aim of the present study was to evaluate the usefulness of the triaxial system in BAE using NBCA. Methods: 12 patients with haemoptysis, 8 males and 4 femaleswith a median age of 64 years (range, 49-88 years), underwent BAE between August 2012 and October 2014. Medical records and images were reviewed, and the technical success rate, clinical success rate, haemoptysis free rate and complications were evaluated. Technical success was defined as the complete cessation of the target artery as confirmed by digital subtraction angiography, whereas clinical success was defined as the cessation of haemoptysis within 24 h of BAE. Recurrent haemoptysis was defined as a total of.30 ml of bleeding per day. Results: The target artery was embolized successfully in all patients, and the technical success rate was 100% (12/12). The cessation of haemoptysis was achieved in 11 out of 12 patients within 24h, and thus, the clinical success rate was 92% (11/12). The 6-, 12- and 24-month haemoptysis-free rates were 89%, 89% and 76%, respectively. No patients exhibited any signs of complications such as spinal ischaemia. Conclusion: BAE using the triaxial system and NBCA appears to be a useful and safe procedure for haemoptysis. Advances in knowledge: The triaxial system contributes to safe and effective BAE using NBCA.
  • Horseshoe Lung Associated with Left Lung Hypoplasia: Case Report and Systematic Review of the Literature., Bando Y, Nakagawa M, Ito K, Ozawa Y, Sakurai K, Shimohira M, Shibamoto Y, Polish journal of radiology, 80, 464 - 469,   2015年, 査読有り
  • Usefulness of CT-guided hookwire marking before video-assisted thoracoscopic surgery for small pulmonary lesions, Kazushi Suzuki, Masashi Shimohira, Takuya Hashizume, Yoshiyuki Ozawa, Ryoji Sobue, Mikio Mimura, Yuji Mori, Hidenori Ijima, Kenichi Watanabe, Motoki Yano, Hiromu Yoshioka, Yuta Shibamoto, JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, 58, (6) 657 - 662,   2014年12月, 査読有り, Purpose: The aim of this study was to evaluate the technical and clinical efficacy and safety of CT-guided hookwire marking before video-assisted thoracoscopic surgery (VATS) for small pulmonary lesions. Materials and Methods: This procedure was performed on 161 lesions in 154 patients (75 men and 79 women; median age, 62 years; age range 23-89 years). Medical records and images were reviewed, and the technical success rate, surgical success rate and complications were evaluated. Technical success was defined as successful hookwire marking at the target site without marker dropping before VATS. Surgical success was defined as negative surgical margins on pathological examination after VATS. Results: There were 97 nodules and 64 ground-glass opacities, and their mean size was 9.8 mm (range 2-34). The technical success rate was 97.5% (157/161). In three of the four failed cases, another hookwire marker was placed, and in the remaining case, VATS was performed without a marker. The surgical success rate was 98.1% (158/161). In the three failed cases, the margin was positive, so lung lobectomy was performed in one case, and the other two cases were observed carefully. Complication rates were as follows: pneumothorax, 37.9% (61/161); focal intrapulmonary haemorrhage, 34.8% (58/139); haemoptysis, 0.6% (1/161); haemothorax, 0% (0/161); air embolism, 0.6% (1/161); dissemination, 0% (0/161); and death, 0% (0/161). Conclusion: CT-guided hookwire marking appears to be useful for VATS, but the procedure may, although rarely, cause severe complications such as air embolism.
  • Feasibility of Time-Resolved MR Angiography for Detecting Recanalization of Pulmonary Arteriovenous Malformations Treated with Embolization with Platinum Coils, Tatsuya Kawai, Masashi Shimohira, Hirohito Kan, Takuya Hashizume, Kengo Ohta, Kenichiro Kurosaka, Masahiro Muto, Kazushi Suzuki, Yuta Shibamoto, JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY, 25, (9) 1339 - 1347,   2014年09月, 査読有り, Purpose: To assess the feasibility of time-resolved magnetic resonance (MR) angiography as a follow-up method after embolization for pulmonary arteriovenous malformations (PAVMs). Materials and Methods: Evaluation of 28 PAVMs in 10 patients previously treated with embolization with platinum coils was performed. The mean observation period after embolization was 49 months. All patients underwent unenhanced chest computed tomography (CT) and time-resolved MR angiography followed by transcatheter digital subtraction angiography within 5 weeks for a definite diagnosis. Two radiologists reviewed the CT and time-resolved MR angiography findings using a blinded method. On CT, the draining veins of the PAVMs were measured before and after embolization, and shrinkage rates were calculated. On time-resolved MR angiography, recanalization was diagnosed when the draining vein or aneurysmal sac or both were enhanced in the pulmonary arterial phase. Correlations between recanalization, the shrinkage rate of the draining vein, and the diagnostic accuracies of CT and time-resolved MR angiography were assessed and compared with digital subtraction angiography. Results: Five lesions could not be measured on CT because of metallic artifacts. The mean shrinkage rates of the draining vein for recanalized and occluded PAVMs were 23% +/- 19 (SD) for recanalized PAVMs and 47% +/- 21 for occluded PAVMs (P = .001). The sensitivity and specificity were 93% and 53%, respectively, when the shrinkage rate threshold was set to 50%. On time-resolved MR angiography, the sensitivity and specificity were 93% and 100%, respectively, for Reader 1 and 100% and 93%, respectively, for Reader 2. The kappa coefficient was 0.86. Conclusions: Time-resolved MR angiography appears to be a feasible method for PAVM follow-up examinations and to provide a more accurate diagnosis of recanalization compared with unenhanced CT.
  • Lumbar puncture-related cerebrospinal fluid leakage on magnetic resonance myelography: is it a clinically significant finding?, Keita Sakurai, Noriyuki Matsukawa, Kenji Okita, Minoru Nishio, Masashi Shimohira, Yoshiyuki Ozawa, Susumu Kobayashi, Takemori Yamawaki, Yuta Shibamoto, BMC ANESTHESIOLOGY, 13, (1) ,   2013年10月, 査読有り, Background: Post-dural puncture headache (PDPH) due to excessive cerebrospinal fluid (CSF) leakage is a well-known complication of lumbar puncture. Although various factors, especially the type of spinal needle, have been demonstrated to be associated with PDPH, the clinical implications of CSF leakage detected on magnetic resonance myelography (MRM) images remain unclear. The objective of this case-control study was to evaluate the association between radiologically visualized CSF leakage and PDPH. Methods: Clinical data including patients' age and gender, types of spinal needle, duration of bed rest, interval between lumbar puncture procedures and MRM studies, and incidence of PDPH were compared between patients who were radiologically-positive and -negative for CSF leakage. Results: Of the 22 patients with definite CSF leakage on MRM images, most were asymptomatic (86%, 19/22). The remaining three patients, who were suffering from PDPH, only complained of headaches and were treated conservatively. In a review of patients' clinical data, there were no significant differences in any parameter including the incidence of PDPH between the 22 patients who were radiologically-positive for CSF leakage and the 31 radiologically-negative patients. Conclusion: The significance of radiologically visualized CSF leakage should not be overestimated, as most such incidents are not associated with PDPH and do not require any treatment.
  • Dual microcather-dual detachable coil technique in embolization for a congenital intrahepatic portosystemic venous shunt (IPSVS), Kazushi Suzuki, Masashi Shimohira, Takuya Hashizume, Yosuke Suzuki, Yuta Shibamoto, MINIMALLY INVASIVE THERAPY & ALLIED TECHNOLOGIES, 22, (5) 316 - 318,   2013年09月, 査読有り, We report a 14-year-old boy with a large intrahepatic portosystemic venous shunt. The shunt seemed to be difficult to coil embolize because it was so large and short. However, it was successfully treated by coil embolization with a new dual microcatheter-dual detachable coil technique.
  • Percutaneous fiducial marker placement under CT fluoroscopic guidance for stereotactic body radiotherapy of the lung: an initial experience, Kengo Ohta, Masashi Shimohira, Hiromitsu Iwata, Takuya Hashizume, Hiroyuki Ogino, Akifumi Miyakawa, Taro Murai, Yuta Shibamoto, JOURNAL OF RADIATION RESEARCH, 54, (5) 957 - 961,   2013年09月, 査読有り, The aim of this study is to describe our initial experience with the VISICOIL, which is the first percutaneous fiducial marker approved for stereotactic body radiotherapy in Japan, and to evaluate its technical and clinical efficacy, and safety. Eight patients underwent this procedure under CT fluoroscopic guidance. One patient had two tumors, so the total number of procedures was nine. We evaluated the technical and clinical success rates of the procedure and the frequencies of complications. Technical success was defined as when the fiducial marker could be placed at the target site, and clinical success was defined as when stereotactic body radiotherapy could be performed without the marker dropping out of position. The technical success rate was 78% (7/9). In one of the two failed cases, we aimed to place the marker inside the tumor, but misplaced it beside the tumor. In the other failed case, we successfully placed the marker beside the tumor as planned; however, the marker migrated to near the pleura after the patient stopped holding their breath. None of the markers dropped out of place, so the clinical success rate was 100% (9/9). The complication rates were as follows: pneumothorax: 56% (5/9), pneumothorax necessitating chest tube placement: 44% (4/9), focal intrapulmonary hemorrhaging: 67% (6/9), hemoptysis: 11% (1/9), mild hemothorax 11% (1/9), air embolism 0% (0/9), and death 0% (0/9). In conclusion, this new percutaneous fiducial marker appears to be useful for stereotactic body radiotherapy due to its good stability.
  • Triaxial System for Embolization of Type II Endo leak After Endovascular Aneurysm Repair, Masashi Shimohira, Takuya Hashizume, Yosuke Suzuki, Kenichiro Kurosaka, Masahiro Muto, Masanori Kitase, Masaru Mizutani, Yuta Shibamoto, JOURNAL OF ENDOVASCULAR THERAPY, 20, (2) 200 - 204,   2013年04月, 査読有り, Purpose: To demonstrate the utility of a triaxial catheter system for embolization of type II endoleak after endovascular aneurysm repair. Technique: The technique is illustrated in 2 patients with sac enlargement owing to persistent type II endoleak of lumbar artery origin. In both cases, the access to the iliolumbar and lumbar arteries was very long and tortuous. For selective catheterization in this situation, a 4-F catheter is advanced through the access site, and 2.7-F microcatheter is inserted into the iliolunnbar artery, followed by a 1.9-F untapered microcatheter. The latter is advanced along with a 0.014-inch microguidewire into the feeding artery. Supported by the 2.7-F microcatheter, the no-taper microcatheter is then navigated through the endoleak to the draining vessel for embolization. Conclusion:This simple-to-use triaxial catheter system seems well suited for superselective embolization of type II endoleaks with very long and tortuous access routes. If glue is used and multiple doses are required, access to the feeding artery is not lost if the smaller microcatheter has to be replaced. J Endovasc Ther. 2013;20:200-204
  • Evaluation of luminal and vessel wall abnormalities in subacute and other stages of intracranial vertebrobasilar artery dissections using the volume isotropic turbo-spin-echo acquisition (VISTA) sequence: A preliminary study, Keita Sakurai, Toshiyasu Miura, Takafumi Sagisaka, Manabu Hattori, Noriyuki Matsukawa, Mitsuhito Mase, Harumasa Kasai, Nobuyuki Arai, Tatsuya Kawai, Masashi Shimohira, Takemori Yamawaki, Yuta Shibamoto, JOURNAL OF NEURORADIOLOGY, 40, (1) 19 - 28,   2013年03月, 査読有り, Objective: To evaluate the utility of 3D variable refocusing flip-angle volume isotropic turbo-spin-echo acquisition (VISTA) imaging, using a 1.5-T MRI unit, which can minimize flow artifacts, due to its sequence-endogenous flow-void capability, in the diagnosis of intracranial verte-brobasilar artery dissection (VAD). Material and methods: The presence of intimal flaps, intramural hematomas, vessel dilatations and abnormal vessel enhancements were evaluated on T1-weighted VISTA images from 18 VAD patients with 20 dissected arteries (15 subacute and five at other stages). Additional gadolinium-enhanced T1 VISTA images were available for 13 patients. The frequency of flow artifacts on T1VISTA imaging in 70 non-dissected arteries in VAD patients and 12 control subjects was also evaluated. Furthermore, in 13 and eight patients, contrast-enhanced three-dimensional (CE3D) imaging with spoiled gradient-recalled (SPGR) acquisition in steady state and electrocardio-graphically gated black-blood (BB) T1-weighted imaging (T1WI) were evaluated to compare visualization of false lumens. Results: Intimal flaps, intramural hematonnas and dilatations were identified on T1 VISTA images in 65% (13/20), 55% (11/20) and 90% (18/20) of VADs, respectively. Abnormal vessel enhancement was recognized in 100% (15/15) of VADs on contrast-enhanced T1VISTA images. Only four normal arteries showed small, thin, linear artifacts. Compared with CE3D-SPGR imaging,T1VISTA imaging depicted false lumens more conspicuously in seven VADs (P=0.02). T1VISTA. also revealed intimal flaps and hematomas as did BB T1WI. Conclusion: T1VISTA imaging may be useful for diagnosing VAD at subacute stages, as it can reveal vessel wall and lumen abnormalities with a minimum of flow artifacts. (C) 2012 Elsevier Masson SAS. All rights reserved.
  • Incarceration of umbilical hernia after radiological insertion of a Denver peritoneovenous shunt, Kengo Ohta, Masashi Shimohira, Takuya Hashizume, Tatsuya Kawai, Kenichiro Kurosaka, Kazushi Suzuki, Kenichi Watanabe, Yuta Shibamoto, JAPANESE JOURNAL OF RADIOLOGY, 31, (3) 208 - 210,   2013年03月, 査読有り, We report a rare complication of incarceration of an umbilical hernia after Denver peritoneovenous shunt placement. A 50-year-old man presented with refractory ascites from liver cirrhosis. He also had an umbilical hernia. Because the ascites became uncontrollable, Denver peritoneovenous shunting was performed. The operation was successful and the ascites decreased. Ten days later, however, incarceration of the umbilical hernia occurred. A surgical repair was performed, but he died 2 days later. The cause of death was considered to be sepsis.
  • Time-resolved Magnetic Resonance Angiography for assessment of recanalization after coil embolization of visceral artery aneurysms., Kurosaka K, Kawai T, Shimohira M, Hashizume T, Ohta K, Suzuki Y, Shibamoto Y, Polish journal of radiology, 78, (1) 64 - 68,   2013年01月, 査読有り
  • Rebleeding after Stent Grafting for the Celiac Artery Bleeding following Extended Pancreaticoduodenectomy., Ohta K, Shimohira M, Hashizume T, Kawai T, Muto M, Honda J, Shibamoto Y, Case reports in vascular medicine, 2013,   2013年, 査読有り
  • Comparison of the radioisotope cisternography findings of spontaneous intracranial hypotension and iatrogenic cerebrospinal fluid leakage focusing on chronological changes, Keita Sakurai, Minoru Nishio, Kazuo Yamada, Masashi Shimohira, Yoshiyuki Ozawa, Noriyuki Matsukawa, Takuya Oguri, Yoshino Ueki, Junko Tohyama, Takemori Yamawaki, Yuta Shibamoto, CEPHALALGIA, 32, (15) 1131 - 1139,   2012年11月, 査読有り, Background: Radioisotope cisternography (RICG) is useful for detecting cerebrospinal fluid (CSF) leakage in spontaneous intracranial hypotension (SIH) patients. However, RICG can cause iatrogenic CSF leakage (ICSFL) due to a lumbar puncture. Objectives: To compare the RICG findings of SIH and ICSFL. Methods: The presence of direct findings suggesting CSF leakage and indirect findings including early visualization of the bladder and absence of radioactivity over the brain convexities were evaluated in seven SIH and six ICSFL patients. Radioisotope clearance was assessed semi-quantitatively. Results: In contrast to the variety of anatomical levels at which direct findings were detected in the SIH patients, the ICSFL patients only displayed direct findings at the lumbosacral level. None of the ICSFL patients displayed direct findings at 1 hour after the tracer injection. Although early visualization of the bladder was depicted in all patients, no activity was visualized over the brain convexities in the SIH patients. In the semi-quantitative analysis, the tracer retention index at 24 hours was lower in the SIH patients than the ICSFL patients. Conclusions: The early appearance of direct findings above the lumbosacral level, the absence of radioactivity over the brain convexities and a low tracer retention index are suggestive of SIH.
  • Clinical usefulness of the triaxial system in super-selective transcatheter arterial chemoembolization for hepatocellular carcinoma, Masashi Shimohira, Hiroyuki Ogino, Tatsuya Kawai, Keita Sakurai, Motoo Nakagawa, Yuta Shibamoto, ACTA RADIOLOGICA, 53, (8) 857 - 861,   2012年10月, 査読有り, Background: Transcatheter arterial chemoembolization (TACE) has been widely performed for inoperable hepatocellular carcinoma (HCC). Super-selective TACE is preferable to non-selective therapy and it is important to advance the catheter tip as close to the tumor as possible in the feeding artery. A new microcatheter with a 1.9-Fr non-tapered tip has recently become available and this new microcatheter can be inserted into a 2.7-Fr. microcatheter. It is called the triple co-axial (triaxial) system. Purpose: To evaluate the clinical usefulness of super-selective TACE for HCC using the triaxial system. Material and Methods: We evaluated 63 HCCs that underwent super-selective TACE. Requirements for inclusion in this study were: (a) HCCs 3 cm or less in diameter; (b) TACE performed by a single operator; and (c) no additional treatment in the absence of local progression. All patients were followed for more than 1 year after TACE. The median follow-up period for surviving patients was 20 months (range, 17-31 months). The conventional system was used in 35 HCCs (control group), and the triaxial system was used in 28 (triaxial group). We reviewed angiographies at TACE and follow-up CT, and then evaluated local tumor status in the two groups. Results: Local tumor control rates at 3, 6, and 18 months were 64%, 36%, and 29%, respectively, in the triaxial group, and 40%, 14%, and 8.6%, respectively, in the control group (P = 0.0086). There were no major complications in either group. Conclusion: The triaxial system appears to be useful for super-selective TACE and may contribute to achieving higher local control rates for HCC.
  • New Coaxial Transseptal Needle for Creation of Atrial Septal Defects in Adult Sheep, Barry T. Uchida, Dusan Pavcnik, Masashi Shimohira, Young Ho Choi, Miran Jeromel, Frederick S. Keller, Josef Roesch, CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY, 34, (3) 620 - 625,   2011年06月, 査読有り, Objectives To introduce a new transseptal (TS) needle assembled in our laboratory-the coaxial TS (CTS) needle-and describe our experience with it in creating experimental atrial septal defects (ASD) in adult sheep. Background With commercially available TS needles, we were not able to consistently perform TS puncture at the fossa ovalis in adult sheep. Material and Methods Ten adult sheep with a mean weight of 63.5 kg were used. The CTS needle consists of four components: a 9F Teflon catheter, a 14-gauge blunt curved-tip metal cannula, a 4F tapered catheter, and a 20-gauge open needle. A transjugular 5F pigtail catheter was used to display the septal anatomy by angiocardiography and was left in place to mark the level of the fossa ovalis. The septum was then probed by a transfemoral 5F curved-tip end-hole catheter. The CTS needle was aligned with the tip of the transjugular catheter, and the TS puncture was performed under fluoroscopic guidance. After documenting a left atrial position, a balloon angioplasty catheter was used for creation of the ASD. Results A small patent foramen ovale was discovered by septal probing in one sheep. All sheep underwent successful TS punctures without complications. The ASD size ranged from 13 to 15 mm. In eight sheep, the ASD was in fossa ovalis. In the first two sheep where the needle was not well aligned with the marking catheter, the ASD was in the septum secundum. No damage to the atrial or other heart structures was found at necropsy. Conclusion The CTS needle is a suitable needle for TS puncture and ASD creation in adult sheep. Proper alignment of the CTS needle with a catheter marking the fossa ovalis is essential for successful puncture.
  • Use of the triaxial microcatheter method in super-selective transcatheter arterial chemoembolisation for hepatocellular carcinoma, M. Shimohira, H. Ogino, T. Kawai, A. Kushita, M. Watanabe, T. Kawaguchi, K. Kurono, Y. Shibamoto, BRITISH JOURNAL OF RADIOLOGY, 84, (998) 184 - 187,   2011年02月, Objectives: Transcatheter arterial chemoembolisation (TACE) has been widely used for inoperable hepatocellular carcinoma (HCC). Super-selective TACE is preferable to non-selective therapy, because it maximises the impact of treatment on the tumour while minimising damage to tumour-free liver parenchyma. It is therefore important to advance the catheter tip as close as possible in the feeding artery. There is now a new microcatheter with a 1.9-Fr tip with no taper, which can be inserted into a 2.7-Fr microcatheter. In this study we describe the new technique of using the two microcatheters called the triaxial microcatheter method. Methods: We evaluated 30 TACE procedures to investigate whether or not the catheter tip could be advanced closer to HCC with the triaxial microcatheter method than with previous TACE using a conventional microcatheter. Results: With conventional microcatheters, the level of embolisation was a lobar artery in 4 cases, segmental in 8 cases, subsegmental in 15 cases and sub-subsegmental in only 1 case. TACE could not be performed in two cases. When using the triaxial microcatheter method the level of embolisation was subsegmental in 8 cases, including 2 in which the level was the same as that with a conventional microcatheter, sub-subsegmental in 13 cases and more distal in 7 cases. In the two cases in which TACE could not be performed with the conventional microcatheter, it could be performed sufficiently using the new method. As a whole, in 28 of the 30 procedures (93%) we could successfully advance a catheter tip closer than with the previous TACE. Conclusion: The triaxial microcatheter method appears to be useful.
  • Twin Valve Caval Stent for Functional Replacement of Incompetent Tricuspid Valve: A Feasibility Animal Study, Jan Sochman, Jan H. Peregrin, Dusan Pavcnik, Barry T. Uchida, Hans A. Timmermans, Masashi Shimohira, Young Ho Choi, Frederick S. Keller, Josef Roesch, CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY, 34, (1) 174 - 179,   2011年02月, 査読有り, To evaluate feasibility of a twin valve caval stent (TVCS) for functional replacement of an incompetent tricuspid valve (TV) in an acute animal study. One swine and three sheep were used in the study. TVCS placement was tested in a swine with a normal TV. TVCS function was tested in three sheep with TV regurgitation created by papillary muscle avulsion. Cardiac angiograms and pressure measurements were used to evaluate TVCS function. Two sheep were studied after fluid overload. TVCS was percutaneously placed properly at the central portions of the superior vena cava (SVC) and inferior vena cava (IVC) in the swine. Papillary muscle avulsion in three sheep caused significant tricuspid regurgitation with massive reflux into the right atrium (RA) and partial reflux into the SVC and IVC. TVCS placement eliminated reflux into the SVC and IVC. After fluid overload, there was enlargement of the right ventricle and RA and significant increase in right ventricle, RA, SVC, and IVC pressures, but no reflux into the IVC and SVC. The results of this feasibility study justify detailed evaluation of TVCS insertion for functional chronic replacement of incompetent TV.
  • Hemosuccus pancreaticus associated with segmental arterial mediolysis successfully treated by transarterial embolization, Naitoh, I, Ando, T, Shimohira, M, Nakazawa, T, Hayashi, K, Okumura, F, Miyabe, K, Yoshida, M, Togawa, H, Sasaki, S, Shibamoto, Y, Joh, T, Journal of the Pancreas, 11, (6) 625 - 629,   2010年11月, 査読有り
  • Continuous Regional Arterial Infusion Therapy for Acute Necrotizing Pancreatitis Due to Mycoplasma pneumoniae Infection in a Child, Motoo Nakagawa, Hiroyuki Ogino, Masashi Shimohira, Masaki Hara, Yuta Shibamoto, CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY, 32, (3) 581 - 584,   2009年05月, 査読有り, A case of acute necrotizing pancreatitis due to Mycoplasma pneumoniae infection was treated in an 8-year-old girl. She experienced acute pancreatitis during treatment for M. pneumoniae. Contrast-enhanced computed tomographic scan revealed necrotizing pancreatitis. The computed tomographic severity index was 8 points (grade E). A protease inhibitor, ulinastatin, was provided via intravenous infusion but was ineffective. Continuous regional arterial infusion therapy was provided with gabexate mesilate (FOY-007, a protease inhibitor) and meropenem trihydrate, and the pancreatitis improved. This case suggests that infusion therapy is safe and useful in treating necrotizing pancreatitis in children.
  • Embolization for Acute Small-Bowel Bleeding from the Collateral Artery of the Superior Mesenteric Left Deep Circumflex Iliac Artery Associated with Narrowing of the Bilateral Common External Iliac Arteries, Masashi Shimohira, Hiroyuki Ogino, Shigeru Sasaki, Hiroko Nishikawa, Yuta Shibamoto, CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY, 32, (2) 374 - 376,   2009年03月, 査読有り, We present a case of acute small-bowel bleeding from the collateral artery of the superior mesenteric-left deep circumflex iliac artery that was successfully managed by transarterial coil embolization.
  • The Use of an Upper-limb-artery Approach and Long Sheaths in Splanchnic Angiography and Interventional Procedures, Masashi Shimohira, Hiroyuki Ogino, Yuji Mori, Hiroko Omiya, Hirochika Suzuki, Yuta Shibamoto, ACTA RADIOLOGICA, 50, (7) 738 - 742,   2009年, 査読有り, Background: The prolonged bed-rest required achieving hemostasis after splanchnic angiography and interventional procedures can be avoided if the upper limb arteries are used. In such procedures, the use of long sheaths capable of reaching the descending aorta may be advantageous. Purpose: To analyze the results of procedures that utilizes an upper-limb-artery approach and long sheaths. Material and Methods: Two hundred forty-two patients with a mean age of 64 years underwent splanchnic angiography and interventional procedures via an upper limb artery using a long sheath (85 cm, 4-French). Repeat examinations were performed on 48 patients and the total number of examinations was 296. The records of these 296 examinations were reviewed and the success rate and complications were evaluated. Results: Overall, 295 of 296 (99.7%) examinations were successful, and one (0.3%) failed. Complications and side effects occurred in six cases (2.0%), a painful sheath manipulation occurred in two examinations (0.7%), and arterial occlusion (including temporary occlusion), hematoma of the puncture site, and pseudoaneurysm occurred in two (0.7%), one (0.3%), and one (0.3%) patient, respectively. Conclusion: The use of a long sheath capable of reaching the descending aorta enables the performance of splanchnic angiography and interventional procedures via the upper limb arteries.
  • Transcatheter Arterial Embolization for Segmental Arterial Mediolysis, Masashi Shimohira, Hiroyuki Ogino, Shigeru Sasaki, Kiichi Ishikawa, Masashi Koyama, Kenichi Watanabe, Yuta Shibamoto, JOURNAL OF ENDOVASCULAR THERAPY, 15, (4) 493 - 497,   2008年08月, 査読有り, Purpose: To report outcomes of transcatheter arterial embolization for segmental arterial mediolysis (SAM), a vascular disorder characterized by angiographically documented fusiform aneurysms separated by areas of normal appearing vessel in the celiac or mesenteric arteries. Case Reports: Four patients (3 men; median age 70 years, range 57-77) had a presumptive diagnosis of SAM; the possibility of vasculitis was ruled out based on clinical and laboratory findings. Three patients were symptomatic, with aneurysm rupture; the fourth patient was diagnosed incidentally. Coil embolization was used in 3 cases and N-butyl cyanoacrylate in the other. There was no re-rupture. One patient developed a focal dissection of the superior mesenteric artery 9 months after middle colic artery embolization. Another patient died of perforation of the lower gastrointestinal tract 3 months after treatment, but the cause was unknown; mesenteric ischemia from embolization and arteriopathy could not be ruled out. Conclusion: Transcatheter embolization is useful for SAM. However, it is likely that the morphology associated with SAM transforms rapidly, so patients undergoing mesenteric artery embolization should be monitored at short intervals. J Endovasc Ther 2008;15:493-497
  • Embolization of a right gastroepiploic artery pseudoaneurysm associated with Churg-Strauss syndrome, Masashi Shimohira, Hiroyuki Ogino, Masanori Kitase, Shigeru Sasaki, Misako Ishii, Yuta Shibamoto, JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY, 19, (2) 301 - 302,   2008年02月, 査読有り
  • Congenital pulmonary airway malformation - CT-pathologic correlation, Masashi Shimohira, Masaki Hara, Masanori Kitase, Mitsuru Takeuchi, Yuta Shibamoto, Kenji Kurono, Shigeki Shimizu, JOURNAL OF THORACIC IMAGING, 22, (2) 149 - 153,   2007年05月, 査読有り, Objectives: Congenital pulmonary airway malformation (CPAM) is classified into 5 subtypes (types 0 to 4). We attempted to correlate computed tomography (CT) findings with those of pathologic examination and evaluated the predictability of the CPAM subtype. Subjects and Methods: We retrospectively reviewed CT findings in 13 pathologically proven cases of CPAM seen between 1981 and 2005. Patient's age ranged from 4 days to 5 years and 10 months. Six were boys and 7 were girls. According to CT findings, lesions with a cyst larger than 2.5 cm, lesions with cysts 2.5 cm or less and solid lesions were classified into groups A, B, and C, respectively. We assumed that Stocker's types 1 and 4, type 2. and types 0 and 3 would correspond to CT groups A, B, and C, respectively. Then, we assessed whether this assumption is correct or not. Results: Eight, 3, and 2 cases were diagnosed as groups A, B, and C, respectively. All of the 8 cases diagnosed as group A were Stocker's type 1. One of the 3 cases diagnosed as group B was type 2, but the remaining 2 were type and type 4, respectively. One of the 2 cases diagnosed as group C was type 3 but the other was type 2. Conclusions: Lesions with the largest cyst being larger than 2.5 cm was type 1. It seemed, however, difficult to distinguish among types 1, 2, and 4 when they consisted of small cystic components and between types 2 and 3 when they appeared as a solid lesion.
  • Embolization for asymptomatic aneurysms of the first jejunal artery, M. Shimohira, H. Ogino, M. Kitase, M. Takeuchi, Y. Shibamoto, VASA-JOURNAL OF VASCULAR DISEASES, 35, (3) 198 - 200,   2006年08月, In a 71-year-old man with a history of coronary artery bypassing using the left internal thoracic and gastroepiploic arteries, the first jejunal artery aneurysms were found by chance at 3D-CTperformed to evaluate conditions of the grafts. He was successfully treated by transcatheter embolization using interlocking detachable coils. During a follow-up period of 5 months, the patient did well and had no sign of intestinal ischemia.

MISC

受賞

  •   2016年04月, アジア太平洋IVR学会, 優秀演題賞
  •   2014年06月, 日本IVR学会, 優秀演題賞

競争的資金

  • 肺動静脈奇形に対する根治治療:ハイドロコイルによる再開通しない塞栓術の確立, 文部科学省, 科学研究費補助金 若手研究(B),   2015年04月 - 2019年03月


Copyright © MEDIA FUSION Co.,Ltd. All rights reserved.