Junji Murakami
Radiation Effects Research Foundation
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Featured researches published by Junji Murakami.
Journal of Computer Assisted Tomography | 1997
Lawrence D. Buadu; Junji Murakami; Sadayuki Murayama; Norihisa Hashiguchi; Shuji Sakai; Satoshi Toyoshima; Kouji Masuda; Syoji Kuroki; Shinji Ohno
PURPOSE Our goal was to review patterns of peripheral enhancement on contrast-enhanced MRI of the breast and to correlate radiologic findings with pathologic features. METHOD We reviewed the MR images of 124 consecutive women with breast lesions. Peripheral enhancement was identified in 35 (32 malignant, 3 benign) lesions. MRI findings were correlated with pathologic features including microvessel density and distribution determined histologically. RESULTS Early peripheral enhancement with centripetal progression was seen in invasive carcinomas with a high peripheral and a low central microvessel density, associated with fibrosis and/or necrosis (n = 18; 15 with central fibrosis, 2 with fibrosis and necrosis, and 1 with necrosis alone). Early peripheral enhancement with minimal or no change in enhancement was seen in both malignant (n = 10) and benign (n = 3) lesions. Delayed peripheral enhancement with centrifugal progression was seen in carcinomas that had an expansive growth pattern and a high marginal vessel density with or without a vascularized rim of connective tissue (n = 4). CONCLUSION Early peripheral enhancement with centripetal progression appears to be fairly specific for carcinomas, whereas early enhancement with minimal or no centripetal progression, although more common in malignant tumors, may be seen in some benign lesions as well.
Journal of Computer Assisted Tomography | 1995
Sadayuki Murayama; Junji Murakami; Hideyuki Watanabe; Shuji Sakai; Satomi Hinaga; Hiroyasu Soeda; Hajime Nakata; Kouji Masuda
Objective We evaluated the intracystic MR signal intensity of mediastinal cystic tnasses to identify characteristic intensity patterns according to histologic type. Materials and Methods Magnetic resonance imaging was performed on 26 cystic mediastinal masses consisting of 8 thymic cysts, 5 bronchogenic cysts, 4 pericardial cysts, 5 cystic teratomas, and 4 cystic neurogenic tumors. Signal intensity ratios of each cyst to muscle were calculated on T1-weighted imaging. Surgical records were reviewed to document the presence of intracystic hemorrhage. Chemical analysis of intracystic fluid was performed in three cases. Results Bronchogenic cysts, cystic teratomas, and cystic neurogenic tumors had relatively high levels of signal intensities. Each pericardial cyst had a lower signal intensity than tnuscle. The signal intensities of thymic cysts were variable. Intracystic hemorrhage was present in 1 bronchogenic cyst, 2 cystic neurogenic tumors, 4 cystic teratomas, and 3 thymic cysts. No hemorrhage was found in any of the pericardial cysts. Sebaceous fluid was present in 1 cystic teratoma. Conclusion The varying intensities of different cysts were considered to reflect the nature of the intracystic fiuid. Since the nature of the fluid can reflect the histology to some extent, T1-weighted MRI will help to differentiate cystic tnediastinal masses. Index Terms Mediastinum, cysts—Histology—Magnetic resonance imaging.
Journal of Computer Assisted Tomography | 1999
Sadayuki Murayama; Junji Murakami; Hidetake Yabuuchi; Hiroyasu Soeda; Kouji Masuda
PURPOSE The purpose of this work was to demonstrate the variety of causes of crazy-paving appearance (CPA) on high resolution CT (HRCT). METHOD To identify cases exhibiting CPA (ground-glass opacity with superimposed interlobular septal thickening and intralobular interstitial thickening) on HRCT, we prospectively searched for them over a period of 29 months. RESULTS We identified 10 cases of CPA on HRCT, including 4 Pneumocystis carinii pneumonia, 1 alveolar proteinosis, 1 usual interstitial pneumonia, 1 pulmonary hemorrhage, 1 acute radiation pneumonitis, 1 adult respiratory distress syndrome, and 1 drug-induced pneumonitis. CONCLUSION CPA can result from a variety of diseases. When we encounter CPA on HRCT, clinical information is necessary for differentiation of these entities.
Journal of Computer Assisted Tomography | 1993
Hajime Nakata; Kanji Egashira; Hideyuki Watanabe; Katsumi Nakamura; Hideo Onitsuka; Sadayuki Murayama; Junji Murakami; Kouji Masuda
The MR appearance of eight bronchogenic cysts is reported. All the cysts appeared homogeneous and were of very high signal intensity, approximating that of CSF on spin-echo T2-weighted imaging, and of relatively high intensity, between that of muscle and subcutaneous fat on T1-weighted imaging. The cysts were round or ovoid and were well demarcated. These findings are consistent with the fluid-containing properties of cysts.
Radiation Medicine | 2006
Madoka Saku; Kengo Yoshimitsu; Junji Murakami; Yusuke Nakamura; Syuuiti Oguri; Tomoyuki Noguchi; Katsuhiko Ayukawa; Hiroshi Honda
PurposeWe analyzed radiography and computed tomography (CT) findings of small bowel perforation due to blunt trauma to identify the keys to diagnosis.Materials and methodsTwelve patients with surgically proven small bowel perforation were retrospectively studied. All patients underwent radiography and CT, and five underwent presurgical follow-up CT. Radiological findings were evaluated and correlated to the elapsed time from the onset of the trauma retrospectively.ResultsRadiography demonstrated free air in only 8% (1/12) and 25% (3/12) at the initial and follow-up examinations, respectively. In contrast, the initial and follow-up CT scans detected extraluminal air in 58% (7/12) and 92% (11/12), respectively. Mesenteric fat obliteration was seen in 58% (7/12) and 75% (9/12) at initial and follow-up CT, respectively. The incidence of both extraluminal air and mesenteric fat obliteration on CT increased as time elapsed, particularly after 8 h. High-density ascites was seen in 75% at initial CT, including two patients without extraluminal air, but was observed in all but one patient at follow-up CT.ConclusionThe chance of detecting extraluminal air increases as time elapses. High-density ascites may be seen without extraluminal air and might be an indirect or precedent sign of small bowel perforation. Radiologists need to be familiar with these radiological features.
Cancer | 1983
Naofumi Hayabuchi; Walter J. Russell; Junji Murakami
Radiographs generated during 20 years of biennial chest radiography of 107 patients with histologically proven lung cancers were reviewed for radiological evidence of slow‐growing lesions. Twenty‐nine of 37 solitary circumscribed peripheral masses which doubled in volume in five or more months prior to any therapy were considered slow growing. By these criteria, 7 (17%) of 41 squamous cell carcinomas were slow growing; whereas 22 (42%) of 52 adenocarcinomas grew slowly. There were no slow‐growing tumors among the 14 anaplastic carcinomas or cancers of other histological type. The mean doubling time for the seven squamous cell carcinomas was 5.7 months; that for the 22 adenocarcinomas was 13.1 months. The cancers of females tended to grow more slowly than did those of males. There was no appreciable difference between the mean age of the 29 patients with slow‐growing lesions and that of the remaining 78. Not only was the majority of cancer in the present study readily detectable by radiographic screening of the chest; patient survival correlated very well with the growth rates of the lesions, including those of seven resected tumors. The survivals of the seven patients with adenocarcinomas whose lesions were resected were no better than those of the remaining adenocarcinoma patients who had no surgical treatment. The results of this study proved that an appreciable percentage of lung cancers do develop slowly, especially adenocarcinomas.
Journal of Computer Assisted Tomography | 1992
Kuniyuki Kaneko; Hideo Onitsuka; Junji Murakami; Hiroshi Honda; Masahiko Kimura; Naotaka Shiraishi; Kouji Masuda
A case of splenic angiosarcoma with siderotic nodules is reported. The tumor was hyperechoic on ultrasound and had high density on CT and very low intensity on MR. Gandy-Gamna nodules (siderotic nodules) were demonstrated histopathogically.
Journal of Trauma-injury Infection and Critical Care | 1998
Sadayuki Murayama; Hideo Onitsuka; Junji Murakami; Yoshikuni Torii; Kouji Masuda; Kazuyoshi Nishihara
Objective The “CT angiogram sign” in dynamic pulmonary CT consists of enhanced branching pulmonary vessels in a homogeneous hypoattenuating consolidation of lung parenchyma and is reportedly useful for diagnosing lobar bronchioloalveolar cell carcinomas. Materials and Methods To identify cases exhibiting the CT angiogram sign, we retrospectively reviewed the reports of 5,500 dynamic incremental CT examinations of the chest. Results We identified the CT angiogram sign in five patients with obstructive pneumonitis due to lung tumors and four patients with pneumonias. Conclusion The CT angiogram sign can be observed in pulmonary consolidation of varying etiologies.
Journal of Computer Assisted Tomography | 1982
Junji Murakami; Walter J. Russell; Naofumi Hayabuchi; Shojiro Kimura
An earlier review of the lateral chest radiographs of 8,610 Hiroshima and Nagasaki Adult Health Study subjects revealed 48 persons with posterior longitudinal ligament ossification (PLLO) in the thoracic region. Seven additional PLLO cases detected outside that observation period brought the total to 55. Among them, 15 patients with neurological signs and/or the greatest degree of thoracic PLLO were selected for computed tomography (CT) of the spine in the present study. Computed tomography proved extremely valuable in identifying the location, shape, and severity of PLLO. In two cases, CT differentiated some lesions previously regarded to be PLLO as actually due to hypertrophie margins of vertebral bodies. Possible explanations are included for the development of the laminated or tandem type PLLO, and PLLO that is located laterally rather than in midline.
Acta Radiologica | 1989
Naofumi Hayabuchi; Walter J. Russell; Junji Murakami
All chest radiographs of 107 proven lung cancer patients who received consecutive biennial chest radiography were reviewed to elucidate problems detecting their cancers, and diagnosing them when initially radiographically detected. Subjects, members of a fixed population sample, originally numbered 20000 persons, 17000 of whom consistently received consecutive biennial chest radiography during examinations for late effects of atomic-bomb radiation. Among the 107 subjects, 64 had radiographic manifestations of cancer; 47 were initially correctly diagnosed; 17 were not. Eleven of the 17 were initially equivocal, diagnosable only after subsequent radiography and retrospective review of serial radiographs. Diagnostic problems consisted of 1) six detection errors with cancer images superimposed on musculoskeletal and cardiovascular structures, reducible by stereoscopic p.a. instead of single p.a. radiography; immediate tentative interpretations; and by comparing earlier with current radiographs. 2) Eight decision errors, wherein cancers mimicked other diseases, were reducible by greater index of suspicion and scrutiny during interpretations.
