Details of a Researcher - Tamura, Masashi

Papers - Tamura, Masashi

Division display 1 - 6 of about 6 ／ All the affair displays >>

Development of human hepatocellular carcinoma in X-linked severe combined immunodeficient pigs: An orthotopic xenograft model

Mishima K., Itano O., Matsuda S., Suzuki S., Onishi A., Tamura M., Inoue M., Abe Y., Yagi H., Hibi T., Kitago M., Shinoda M., Kitagawa Y.

PLoS ONE (PLoS ONE) 16 ( 3 March ) e0248352 2021.03

Hepatocellular carcinoma (HCC) is the fifth most common primary tumor and the third leading cause of cancer-related deaths worldwide. Rodent models of HCC have contributed to the advancement of studies investigating liver carcinogenesis, tumor-host interactions, and drug screening. However, their small size renders them unsuitable for surgical or clinical imaging studies, necessitating the development of larger-size HCC models. Here, we developed a xenograft model of human HCC in X-linked interleukin-2 receptor gamma chain gene (Il2rg)-targeted severe combined immunodeficient (SCID) pigs. HepG2 cell suspension in serum-free medium containing 50% membrane matrix was directly injected into the liver parenchyma of eight X-linked Il2rg-targeted SCID pigs (6.6-15.6 kg) via ultrasonography- guided percutaneous puncture. Tumor engraftment was evaluated weekly using ultrasonography, and cone-beam computed tomography was performed during arterial portography (CTAP) and hepatic arteriography (CTHA) to evaluate the hemodynamics of engrafted tumors. The engrafted tumors were histologically analyzed following necropsy and assessed for pathological similarities to human HCCs. Macroscopic tumor formation was observed in seven of the eight pigs (simple nodular tumors in three and multinodular tumors in four). Engrafted tumors were identified as low-echoic upon ultrasonography and as perfusion-defect nodules on the CTAP images. Meanwhile, CTHA showed that the tumors were hyperattenuating. Further, histopathological findings of the engrafted tumors were consistent with those of human HCC. In conclusion, the porcine model of human HCC, successfully generated herein, might help develop more effective therapeutic strategies for HCC.

Access to Document (DOI)

Arteriovenous malformation on the sole of the foot treated successfully by embolization

Yuzaki I., Aramaki-Hattori N., Tamura M., Torikai H., Okabe K., Sakai S., Nakatsuka S., Jinzaki M., Kishi K., Inoue M.

Radiology Case Reports (Radiology Case Reports) 15 ( 12 ) 2621 - 2626 2020.12

© 2020 Arteriovenous malformations of the sole of the foot are rare and can cause disturbances in normal living activities. We report a case of a plantar arteriovenous malformation in a 24-year-old male with pain and difficulty in walking. The arteriovenous malformation was complex, with a large and poorly marginated nidus, so we considered that with surgical resection, walking disabilities would be inevitable. When surgical removal of vascular mass is difficult, embolization alone can be effective. Therefore, he was treated with 4 therapeutic embolization procedures. Transvenous approaches to the venous sac and direct punctures of the nidus was performed. The nidus was successfully eradicated by embolization using alcohol, resulting in the disappearance of associated symptoms. Appropriate imaging is essential for diagnosis and evaluation of treatment. We were successful in achieving improved quality of life and satisfaction for a rare and difficult case by percutaneous embolization and sclerotherapy.

Access to Document (DOI)

Predictors of Occlusion of Hepatic Blood Vessels after Irreversible Electroporation of Liver Tumors

Tamura M., Pedersoli F., Schulze-Hagen M., Zimmerman M., Isfort P., Kuhl C.K., Schmitz-Rode T., Bruners P.

Journal of Vascular and Interventional Radiology (Journal of Vascular and Interventional Radiology) 31 ( 12 ) 2033 - 2042.e1 2020.12

ISSN 10510443

© 2020 SIR Purpose: To examine predictors of midterm occlusion in portal and hepatic veins within or adjacent to the ablation zone after irreversible electroporation (IRE) of liver tumors. Materials and Methods: This retrospective cohort analysis included 39 patients who underwent CT-guided IRE of liver tumors. Vessels within or adjacent to the ablation zone were identified on CT images acquired immediately after the procedure, and the positional relationships with the ablation zone (within/adjacent), locations (proximal/distal), and diameters (< 4 mm or ≥ 4 mm) were evaluated. Using contrast-enhanced follow-up scans, each vessel was classified as patent, stenosed, or occluded. Associations between vessel occlusion and each variable were investigated. Results: Overall, 33 portal veins and 64 hepatic veins were analyzed. Follow-up scans showed occlusion in 12/33 (36.7%) portal veins and 17/64 (26.6%) hepatic veins. Vessels within the ablation zone were occluded significantly more frequently than vessels adjacent to the ablation zone (portal: 55.6% [10/18] vs 13.3% [2/15], P = .04; hepatic: 45.4% [15/33] vs 6.4% [2/31], P = .011). Vessels with a diameter < 4 mm were also occluded significantly more frequently than vessels with a diameter ≥ 4 mm (portal: 72.7% [8/11] vs 18.1% [4/22], P = .011; hepatic: 54.8% [17/31] vs 0% [0/33], P < .001). The respective positive and negative predictive values for occlusion of vessels categorized as both within and < 4 mm were 88% (7/8) and 82% (20/25) for portal veins and 79% (15/19) and 96% (43/45) for hepatic veins. Conclusions: Midterm vessel occlusion after liver IRE could be predicted with relatively high accuracy by assessing ablation location and vessel diameter.

Access to Document (DOI)

Successful depiction of systemic collateral supply to pulmonary artery in CTEPH using time-resolved 4D CT angiography: a case report

Tamura M., Kawakami T., Yamada Y., Kataoka M., Nakatsuka S., Fukuda K., Jinzaki M.

Pulmonary Circulation (Pulmonary Circulation) 10 ( 2 ) 2045894019881065 2020

ISSN 20458932

© The Author(s) 2020. A 49-year-old man with CTEPH (pre-procedural mean pulmonary artery pressure: 36 mmHg) underwent balloon pulmonary angioplasty. Chronic total occlusion of the left inferior pulmonary artery trunk was observed. To evaluate the collateral vessels of the chronic total occlusion, 4D-CTA was performed. The examination was performed using a 256-row detector CT system using the test bolus tracking method. 4D-CTA showed the bronchial artery-to-left inferior pulmonary artery collateral supply, which was confirmed by a selective bronchial artery angiography. The patient’s symptoms improved with balloon pulmonary angioplasty of the other stenotic lesions. 4D-CTA can noninvasively evaluate the anatomy and hemodynamics of multiple systemic collaterals simultaneously. This technique can support interventions in systemic artery-to-pulmonary artery collaterals, such as embolization, and could be helpful in challenging balloon pulmonary angioplasty interventions for chronic total occlusion to identify vessel structures distal to the chronic total occlusion and collateral channels for a retrograde approach.

Access to Document (DOI)

Imaging Findings of Atypical Type II Endoleak Through Vasa Vasorum After Abdominal Endovascular Aneurysm Repair

Torikai H., Inoue M., Nakatsuka S., Tamura M., Yashiro H., Yoshitake A., Shimizu H., Jinzaki M.

CardioVascular and Interventional Radiology (CardioVascular and Interventional Radiology) 41 ( 1 ) 186 - 190 2018.01

ISSN 01741551

© 2017, Springer Science+Business Media, LLC and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE). A type II endoleak (T2EL) is the most common endoleak after endovascular aneurysm repair (EVAR), and a persistent T2EL has been occasionally associated with aneurysmal enlargement. Typical findings of a T2EL consist of an endoleak cavity with inflow and outflow arteries of aortic branch vessels. However, an atypical T2EL, in which hypertrophied vasa vasorum and enlargement of a thrombosed aneurysm are observed, has no endoleak cavity. We have seen three cases of continuous aortic aneurysmal growth after EVAR caused by atypical T2ELs without endoleak cavities through developed vasa vasorum. In this report, the imaging findings of selective angiography and dynamic computed tomography of these cases are reviewed.

Access to Document (DOI)

第8回日本IVR学会夏季学術セミナー『B-RTOとNBCA塞栓術』受講生の受講前後の診療行動の調査

米虫敦, 瀧川政和, 西田典史, 山本晃, 松井広登, 前田弘彰, 小林薫, 山本聡, 明神和紀, 橋本毅, 松永敬二, 佐々木真弓, 高橋誠, 若宮誠, 不破相勲, 八神俊明, 藪田実, 野見山弘行, 阿知波左千子, 谷掛雅人, 渡邉啓太, 原口貴史, 今峰倫平, 塚田実郎, 秋山直子, 内ノ村聡, 人見次郎, 保本卓, 中村純寿, 竹口隆也, 田村全, 佐藤浩三, 神谷実佳, 西濱晴香, 森木健生, 瀬之口輝寿, 石川祐一, 長谷聡一郎, 中塚誠之, 山門享一郎, 小泉淳, 廣田省三, 吉岡哲也, 齋藤博哉, 石口恒男, 栗林幸夫, 狩谷秀治, 谷川昇, 澤田敏

IVR: Interventional Radiology ((一社)日本インターベンショナルラジオロジー学会) 27 ( 1 ) 56 - 59 2012.02

ISSN 1340-4520

第8回IVR学会夏季学術セミナー「B-RTOとNBCA塞栓術」の受講による、セミナー受講生のその後の診療行動の変化を検討した。全ての受講生がセミナーのプログラムを終了することができ、26例から調査票を回収した。受講生の所属施設の状況は、一施設あたりのIVR担当医は平均4.1人/施設、年間IVR件数は平均392件/施設、年間B-RTO件数は平均7.2件/施設、年間NBCA塞栓術件数は7.8件/施設であった。B-RTOの診療行動の変化セミナー受講時のB-RTOの術者経験者は15例、術者または助手経験者は24例であった。セミナー受講前6ヵ月間にB-RTO術者経験した者は11例、助手経験を含むと18例であった。セミナー受講時のNBCA塞栓術の術者経験者は13例、術者または助手経験者は17例であった。セミナー受講後6ヵ月間にNBCA塞栓術の術者経験した者は9例、助手経験を含むと15例であった。

　 Previous page - Next page 　