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Dive into the research topics where Shozo Hirota is active.

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Featured researches published by Shozo Hirota.


CardioVascular and Interventional Radiology | 2006

Cone-Beam CT with Flat-Panel-Detector Digital Angiography System: Early Experience in Abdominal Interventional Procedures

Shozo Hirota; Norio Nakao; Satoshi Yamamoto; Kaoru Kobayashi; Hiroaki Maeda; Reiichi Ishikura; Koui Miura; Kiyoshi Sakamoto; Ken Ueda; Rika Baba

We developed a cone-beam computed tomography (CBCT) system equipped with a large flat-panel detector. Data obtained by 200° rotation imaging are reconstructed by means of CBCT to generate three-dimensional images. We report the use of CBCT angiography using CBCT in 10 patients with 8 liver malignancies and 2 hypersplenisms during abdominal interventional procedures. CBCT was very useful for interventional radiologists to confirm a perfusion area of the artery catheter wedged on CT by injection of contrast media through the catheter tip, although the image quality was slightly degraded, scoring as 2.60 on average by streak artifacts. CBCT is space-saving because it does not require a CT system with a gantry, and it is also time-saving because it does not require the transfer of patients.


Journal of Thoracic Imaging | 1993

Interstitial lung disease in rheumatoid arthritis: assessment with high-resolution computed tomography.

Masahiko Fujii; Shuji Adachi; Tadafumi Shimizu; Shozo Hirota; Sako M; Michio Kono

Interstitial lung disease (ILD) is a frequent manifestation of rheumatoid arthritis (RA), and it has a close bearing on the prognosis of RA patients. Computed tomography (CT) has been shown to be excellent for the diagnosis of diffuse lung disease. In this study chest radiographs and high-resolution CT (HRCT) scans were obtained in 91 patients with RA to evaluate their ILD precisely. By HRCT 43 patients could be diagnosed as having interstitial pneumonitis (IP), and 5 could be diagnosed as having bronchiolitis. The remaining 43 patients were normal by HRCT. Chest radiographic findings were consistent with the HRCT findings in approximately 50% of patients with IP. HRCT was superior to chest radiographs for the detection of early interstitial changes. The histogram of HRCT values might be a useful adjunct to HRCT diagnosis by adding some degree of objectivity. HRCT is useful for the diagnosis of ILD in patients with RA.


European Radiology | 2006

Endovascular obliteration of bleeding duodenal varices in patients with liver cirrhosis

Carlos A. Zamora; Koji Sugimoto; Masakatsu Tsurusaki; Kenta Izaki; Tetsuya Fukuda; Shinichi Matsumoto; Yoichiro Kuwata; Ryota Kawasaki; Takanori Taniguchi; Shozo Hirota; Kazuro Sugimura

The purpose of this paper is to describe our experience with endovascular obliteration of duodenal varices in patients with liver cirrhosis and portal hypertension. Balloon-occluded transvenous retrograde and percutaneous transhepatic anterograde embolizations were performed for duodenal varices in five patients with liver cirrhosis, portal hypertension, and decreased liver function. All patients had undergone previous endoscopic treatments that failed to stop bleeding and were poor surgical candidates. Temporary balloon occlusion catheters were used to achieve accumulation of an ethanolamine oleate–iopamidol mixture inside the varices. Elimination of the varices was successful in all patients. Retrograde transvenous obliteration via efferent veins to the inferior vena cava was enough to achieve adequate sclerosant accumulation in three patients. A combined anterograde–retrograde embolization was used in one patient with balloon occlusion of afferent and efferent veins. Transhepatic embolization through the afferent vein was performed in one patient under balloon occlusion of both efferent and afferent veins. There was complete variceal thrombosis and no bleeding was observed at follow-up. No major complications were recorded. Endovascular obliteration of duodenal varices is a feasible and safe alternative procedure for managing patients with portal hypertension and hemorrhage from this source.


Techniques in Vascular and Interventional Radiology | 2013

The conventional balloon-occluded retrograde transvenous obliteration procedure: indications, contraindications, and technical applications.

Wael E. Saad; Takashi Kitanosono; Jun Koizumi; Shozo Hirota

Transvenous obliteration of gastric varices can be performed from the systemic venous side (draining veins or shunts) or from the portal venous side (portal afferent feeders). Balloon-occluded transvenous obliteration from the systemic veins is referred to as balloon-occluded retrograde transvenous obliteration (BRTO) and balloon-occluded transvenous obliteration from the portal veins is referred to as balloon-occluded antegrade (anterograde) transvenous obliteration (BATO). BRTO is the conventional balloon-occluded transvenous obliteration procedure and BATO is considered an alternative or adjunctive approach. This is because, from a technical standpoint, the least invasive choice of access or approach for balloon-occluded transvenous obliteration of gastric varices is the traditional or conventional transrenal route. The objective of BRTO or BATO or both is complete obliteration of the gastric varices with preservation of the anatomical hepatopetal flow of the splenoportal circulation. This article reviews the indications, contraindications, and technical considerations of the conventional BRTO procedure. The indications of concomitant portal venous modulators such as splenic embolization or the creation of a transjugular intrahepatic portosystemic shunt or both are also discussed.


Radiation Medicine | 2006

Evaluation of vascular supply with cone-beam computed tomography during intraarterial chemotherapy for a skull base tumor.

Reiichi Ishikura; Kumiko Ando; Yuki Nagami; Satoshi Yamamoto; Koui Miura; Ajaya R. Pande; Tosyiko Yamano; Shozo Hirota; Norio Nakao

A cone-beam lowers the X-ray exposure level and the contrast material dose used compared to those for the conventional angiography-computed tomography (angio-CT) technique. Herein we present a patient with a metastatic skull base bone tumor in which the subtraction image of cone-beam CT with a flat panel detector was useful for evaluating the vascular supply during superselective intraarterial chemotherapy. Although the image quality of cone-beam CT is poorer than that of conventional angio-CT, the cone-beam CT system is sufficient for clinical use.


European Journal of Radiology | 2016

Correlation of the SUVmax of FDG-PET and ADC values of diffusion-weighted MR imaging with pathologic prognostic factors in breast carcinoma

Kazuhiro Kitajima; Toshiko Yamano; Kazuhito Fukushima; Yasuo Miyoshi; Seiichi Hirota; Yusuke Kawanaka; Mouri Miya; Hiroshi Doi; Koichiro Yamakado; Shozo Hirota

PURPOSE To correlate both primary lesion maximum standardized uptake values (SUVmax) of FDG-PET/CT, and apparent diffusion coefficient (ADC) values of diffusion-weighted imaging (DWI) with clinicopathologic prognostic factors in patients with breast carcinoma. MATERIALS AND METHODS 214 patients with 216 mass-type invasive breast carcinomas underwent whole-body FDG-PET/CT and 3-Tesla breast MRI including DWI before initial therapy. The primary tumors SUVmax and ADC values were measured using FDG-PET/CT and DWI, respectively. Histologic analysis parameters included tumor size, expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki-67, nuclear grade, histology subtype, and axillary lymph node (LN) metastasis. The relationships among SUVmax, ADC values, and pathologic prognostic factors were evaluated. RESULTS The mean SUVmax and ADCmean were 5.63±3.79 (range, 1.2-24.17) and 894±204×10(-6)mm(2)/s (range, 452-1550×10(-6)), respectively. There was a significant but weak inverse correlation between the SUVmax and ADCmean values (correlation coefficient r=-0.30, p<0.0001). SUVmax was associated with numerous prognostic factors such as tumor size (p<0.0001), expression levels of ER (p=0.00041), PR (p=0.00028), HER2 (p=0.00021), and Ki-67 (p<0.0001), nuclear grade (p<0.0001), histology subtype (p=0.00061), axillary LN metastasis (p<0.0001), and TNM staging (p<0.0001). Meanwhile, ADCmean value was associated with tumor size (p=0.013), expression of Ki-67 (p=0.0010), histology subtype (p=0.00013), axillary LN metastasis (p=0.00059), and TNM staging (p=0.0011). CONCLUSIONS Primary tumor SUVmax on FDG-PET/CT has a stronger relationship with known prognostic parameters and may be a more useful for predicting the prognosis of breast carcinoma than ADC values.


Radiation Medicine | 2006

Balloon-occluded retrograde transvenous obliteration for portal hypertension.

Shozo Hirota; Kaoru Kobayashi; Hiroaki Maeda; Satoshi Yamamoto; Norio Nakao

Currently in Japan more than 1.5 million patients have viral hepatitis or hepatic cirrhosis, which may lead to portal hypertension. Thus, treatment of esophageal or gastric varices due to portal hypertension has become important in the clinician’s daily practice. The treatment for portal hypertension includes endoscopic treatment, surgical treatment, interventional radiology (IR) using a catheter, and conservative therapy. In recent years, IR treatment using a catheter has become an important and leading treatment for portal hypertension because of the extensive range of procedures available. IR treatment has made rapid progress because of the development of techniques such as transjugular intrahepatic portosystemic shunt (TIPS) and balloon-occluded retrograde transvenous obliteration (B-RTO). IR has extended its armamentarium with percutaneous transhepatic esophageal varices embolization (PTO) and partial splenic arterial embolization (PSE). Surgical operations such as esophageal transection and Hassab’s operation, as well as endoscopic treatment, have mainly targeted esophageal varices. There are no effective treatments to alleviate the symptoms of portal hypertension (portal hypertensive gastropathy, refractory ascites, gastric varices, refractory esophageal varices, duodenal varices, hypersplenism, shunt hepatic encephalopathy), which therefore have tended not to be sufficiently treated up to now, with only conservative treatment given. Today, however, IR has an excellent treatment effect even on these entities. In particular, B-RTO is a treatment method developed in Japan, and the research, including ours, has clarified that it is not only excellent treatment for gastric varices but improves hepatic function. Furthermore, it is possible to apply B-RTO to portal hypertension with shunt. In this report, we discuss the current situation and development including changes in the treatment method, focusing on the role of B-RTO among the IR techniques for portal hypertension.


CardioVascular and Interventional Radiology | 2006

Bleeding Duodenal Varices Successfully Treated with Balloon-Occluded Retrograde Transvenous Obliteration (B-RTO) Assisted by CT During Arterial Portography

Masakatsu Tsurusaki; Koji Sugimoto; Shinichi Matsumoto; Kenta Izaki; Tetsuya Fukuda; Yoshinobu Akasaka; Masahiko Fujii; Shozo Hirota; Kazuro Sugimura

A 60-year-old woman with massive hemorrhage from duodenal varices was transferred to our hospital for the purpose of transcatheter intervention. Although digital subtraction arterial portography could not depict the entire pathway of collateral circulation, the efferent route of the duodenal varices was clearly demonstrated on subsequent CT during arterial portography. Balloon-occluded retrograde transvenous obliteration (B-RTO) of the varices was performed via the efferent vein and achieved complete thrombosis of the varices.


CardioVascular and Interventional Radiology | 2007

Radiologic Variations in Gastrorenal Shunts and Collateral Veins from Gastric Varices in Images Obtained Before Balloon-Occluded Retrograde Transvenous Obliteration

Hiroaki Maeda; Shozo Hirota; Satoshi Yamamoto; Kaoru Kobayashi; Keisuke Arai; Yoshiya Miyamoto; Tetsuya Fukuda; Koji Sugimoto; Norio Nakao

PurposeTo investigate variations in the features of gastrorenal shunts and collateral veins shown by balloon-occluded retrograde venography (B-RTV) and by superior mesenteric and celiac arteriography.MethodsA retrospective analysis was performed of the variation in these features on B-RTV and arteriography images obtained from 130 patients who have undergone these studies prior to balloon-occluded retrograde transvenous obliteration at our hospital since 1993.ResultsAt least one gastrorenal shunt was revealed in 97% (126/130) of cases. Types of gastrorenal shunts observed were as follows: only one main gastrorenal shunt, 94% (118/126) of cases; two main gastrorenal shunts with a ring-like appearance, 3% (4/126); and some gastrorenal shunts to the left renal vein, 3% (4/126). Collateral veins detected were as follows: left inferior phrenic vein, 75% (95/126) of cases; pericardiacophrenic vein, 40% (50/126); gonadal vein, 13% (16/126); retroperitoneal veins, 65% (82/126).ConclusionIt is very important to know the exact configuration of any gastrorenal shunts in order to guide advancement of the balloon catheter into the shunt and to avoid unexpected injection of the sclerosing agent.


CardioVascular and Interventional Radiology | 2004

Application of Balloon-Occluded Retrograde Transvenous Obliteration to Gastric Varices Complicating Refractory Ascites

Tetsuya Fukuda; Shozo Hirota; Shinichi Matsumoto; Koji Sugimoto; Masahiko Fujii; Masakatsu Tsurusaki; Kenta Izaki; Kazuro Sugimura

We report two cases of gastric varices complicated by massive ascites that disappeared after balloon-occluded retrograde transvenous obliteration (B-RTO). The first patient had progressive gastric varices that continued to enlarge even after three episodes of esophagogastric variceal bleeding, and the second patient was admitted to our hospital because of the bleeding from gastric varices. After B-RTO procedures in both patients, significant improvement of the ascites, hepatic function reserve, and hypoalbuminemia was observed. Although further experience is needed, our experience points to the likelihood of the amelioration of ascites after B-RTO.

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Hiroshi Doi

Hyogo College of Medicine

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Yasuhiro Takada

Hyogo College of Medicine

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Kumiko Ando

Hyogo College of Medicine

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Masao Tanooka

Hyogo College of Medicine

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H. Inoue

Hyogo College of Medicine

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