Yoshiaki Narimatsu
Keio University
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Featured researches published by Yoshiaki Narimatsu.
Journal of Computer Assisted Tomography | 2000
Masahiro Jinzaki; Akihiro Tanimoto; Makio Mukai; Eiji Ikeda; Seiji Kobayashi; Yuji Yuasa; Yoshiaki Narimatsu; Masaru Murai
Purpose To correlate the enhancement pattern of double-phase helical computed tomography (CT) of small renal parenchymal neoplasms with pathologic findings and tumor angiogenesis, and evaluate whether the enhancement pattern would be useful in differentiating the histomorphologic types of small renal parenchymal neoplasms. Materials and Methods Double-phase helical CT (5 mm slice) of the corticomedullary phase (CMP) and late nephrographic phase (NP) was performed in 40 surgically resected renal neoplasms <3.5 cm. The patterns of CT attenuation value and homogeneity were correlated with the subtypes of neoplasms, microvessel density, and the existence of intratumoral necrosis or hemorrhage. Results Clear cell renal cell carcinomas (RCC) (n = 29) showed a peak attenuation value in the CMP of >100 HU [Hounsfield units]. Chromophobe cell RCC (n = 2) showed a peak attenuation value in the CMP of <100 HU. Papillary RCC (n = 5) showed a gradual enhancement with the attenuation value in the CMP of <100 HU. However oncocytomas (n = 2) and metanephric adenomas (n = 2) also showed patterns similar to these subtypes of RCC. The degree of enhancement in the CMP correlated with microvessel density (r = 0.87). All tumors with an homogeneous enhancement pattern did not show necrosis or hemorrhage on histologic specimen. Conclusion The enhancement pattern in double-phase helical CT was different among the subtypes of RCC, and correlated with microvessel density or the existence of intratumoral necrosis or hemorrhage. However it did not differentiate between RCC and other solid tumors.
Journal of Computer Assisted Tomography | 1987
Minoru Yamato; Kunio Ido; Mutsumi Izutsu; Yoshiaki Narimatsu; Kyoichi Hiramatsu
The CT and ultrasound features of retained sponges (gossypibomas) are described in six patients. They are well-circumscribed cystic masses without surrounding edema. The retained sponges or towels were correctly identified in only three cases. In the other three cases retained sponges were organized and lost their original configuration. Gas was seen in one case and calcification in two cases. Gossypibomas should be included in the differential diagnosis in all patients with a well-circumscribed cystic mass in the abdomen and with a history of previous laparotomy.
Cancer Chemotherapy and Pharmacology | 1992
Seiji Kobayashi; Yoshiaki Narimatsu; Kenji Ogawa; Subaru Hashimoto; Seishi Nakatsuka; Hiroshi Miura; Hirokuni Ohzono; Wei Jei Ka; Kunio Ido; Kyoichi Hiramatsu; Toshiharu Tsuzuki; Masaharu Tsuchiya
SummaryThe experimental and pharmacological characteristics of various formulations of an anticancer agent (epirubicin, EPI) and lipiodol were evaluated in vitro and in vivo. Three forms of EPI-lipiodol, i.e., an oil-in-water type of emulsion (O/W type), a water-in-oil type of emulsion (W/O type), and a suspension (S type), were prepared and investigated for their stability. An O/W-type emulsion using a stock solution of Iopamidol as the solvent for EPI was the most stable form in the stationary state in vitro. In 16 patients with malignant liver tumors (14 hepatocellular carcinomas and 2 liver metastases), the three forms of EPI-lipiodol were injected into the proper hepatic artery. The plasma EPI level was monitored periodically and analyzed pharmacokinetically. No significant difference in the pharmacokinetics of EPI was detected among the O/W, W/O, and S types.
Urology | 1984
Seido Jitsukawa; Hiroshi Tazaki; Masaaki Tachibana; Yoshiaki Narimatsu; Nobuhiro Deguchi; Kyoichi Hiramatsu; Masaru Murai
Transcatheter injection of ethanol into the renal artery was utilized in 11 patients with hypernephromas, clincally staged C or D, in an attempt to produce renal devitalization. Complete disappearance of the tumor neovascularity was achieved in 9 of 11 patients. Renal divitalization with ethanol injection is safer and more effective than the embolizing technique utilized hitherto and should be included in the primary treatment of hypernephroma in selected cases or in conjunction with other procedures to induce chemical nephrectomy.
Journal of Vascular and Interventional Radiology | 2017
Hideyuki Torikai; Ichiro Hasegawa; Masahiro Jinzaki; Yoshiaki Narimatsu
We report 5 patients with hemoptysis due to infectious pulmonary artery pseudoaneurysm (PAP) treated with endovascular embolization using N-butyl cyanoacrylate (NBCA) injected via bronchial and nonbronchial systemic arterial approaches. Infectious diseases included inactive tuberculosis (n = 3), nontuberculous mycobacteriosis (n = 1), and chronic infection of unknown origin (n = 1). Seven PAPs were detected on selective systemic angiography, and injection of NBCA was performed. Disappearance of all PAPs was confirmed on systemic arteriography after the intervention. In all patients, hemoptysis was stopped without major complications, and it did not recur during the follow-up period (mean, 351 d; range, 285-427 d).
Journal of Vascular and Interventional Radiology | 2015
Jitsuro Tsukada; Ichiro Hasegawa; Hideyuki Torikai; Koichi Sayama; Masahiro Jinzaki; Yoshiaki Narimatsu
This study reports 6 cases of hemoptysis originating from infectious pulmonary artery pseudoaneurysms (PAPs). Selective pulmonary angiography revealed PAPs in 5 cases, and segmental pulmonary artery embolization was performed using coils and gelatin sponge particles. Systemic arterial embolization also was performed in 5 cases because of inadequate initial control or for shunts from systemic to pulmonary arteries. At a median follow-up time of 9 months (range, 25 d to 25 mo), no recurrence occurred, although 2 patients died of respiratory failure. Segmental artery embolization combined with systemic artery embolization may be useful in patients with hemoptysis secondary to PAPs.
Acta Radiologica | 2001
Yoshiko Tamura; Masahiro Jinzaki; Kiyoshi Ohkuma; Yoshiaki Narimatsu; Subaru Hashimoto; Akihiro Tanimoto; K. Hiramatsu
Purpose: To compare the ability of power Doppler ultrasonography (PDUS) with that of renal angiography for assessment of renal tumor vessels. Material and Methods: We performed PDUS and angiography in 52 histologically proven renal parenchymal tumors (50 renal cell carcinomas (RCCs) and 2 oncocytomas), and compared vascularity on PDUS and angiography. The vascularity of PDUS was graded as follows: grade 0 - no recognizable tumor vessel; grade 1 - hypovascular to surrounding renal interlobar arteries; grade 2 - hyper- or isovascular to surrounding renal interlobar arteries. Results: With PDUS, 41 tumors were grade 2 and 11 were grade 1. With angiography, 44 lesions had iso/hypervascular pattern, 6 hypovascular pattern, and 2 were judged to be avascular. Among 44 iso/hypervascular tumors, 41 were grade 2, and 3 were grade 1. These latter 3 were located deeper than 7 cm. Six hypovascular tumors and 2 avascular tumors were grade 1. The 2 avascular tumors were small and hypovascular. The κ-level of agreement was 0.81. Conclusion: There was very good agreement betweeen PDUS and angiography in visualizing renal tumor vessels. PDUS appears appropriate for assessing renal tumor vascularity as compared to angiography in small and hypovascular lesions, but deep location reduced the detectability of tumor vessels with PDUS.
Radiology | 1997
Masahiro Jinzaki; Akihiro Tanimoto; Yoshiaki Narimatsu; Kiyoshi Ohkuma; Tadayoshi Kurata; Hiroshi Shinmoto; Kyoichi Hiramatsu; Makio Mukai; Masaru Murai
Journal of Magnetic Resonance Imaging | 1998
Hiroshi Shinmoto; Yuji Yuasa; Akihiro Tanimoto; Yoshiaki Narimatsu; Masahiro Jinzaki; Kyoichi Hiramatsu; Makio Mukai
Diagnostic and interventional radiology | 2006
Osamu Tanaka; Subaru Hashimoto; Yoshiaki Narimatsu; Hirokazu Fujiwara; Tadayoshi Kurata; Shigeo Okuda; Takuji Yamagami; Tsunehiko Nishimura; Kyoichi Hiramatsu; Sachio Kuribayashi