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Dive into the research topics where Masahiro Komori is active.

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Featured researches published by Masahiro Komori.


Japanese Journal of Radiology | 2011

Unusual presentation of an esophageal foreign body granuloma caused by a fish bone: usefulness of multidetector computed tomography

Kazufumi Kikuchi; Daisuke Tsurumaru; Kiyohisa Hiraka; Masahiro Komori; Nobuhiro Fujita; Hiroshi Honda

A 68-year-old woman had throat pain while eating fish. The pain gradually disappeared with no treatment. She visited her doctor for a medical checkup 1 year later, and an esophageal tumor was suspected. A double-contrast esophagogram revealed luminal stenosis with a mass-like defect in the middle esophagus. Esophagogastroduodenoscopy (EGD) showed smooth-surface stenosis with a retracted fold. Endoscopic ultrasonography (EUS) showed a hypoechoic mass in the submucosal layer and a well-defined linear hyperechoic structure forming a posterior acoustic shadow within the mass. A computed tomography (CT) examination was then performed using an Aquilion 64-detector row CT scanner, and a high attenuation linear structure was found in the lesion that was visualized as a fish bone-like structure on reconstructed CT images. Endoscopic removal of the fish bone was impossible, and a surgical operation would have been too invasive for a lesion suspected of being benign. The patient had no complaint related to the esophageal lesion itself and no sign of gastrointestinal tract complications. Accordingly, regular follow-up was recommended for the esophageal lesion. Follow-up examination including EGD, esophagography, and CT performed 1 year later showed that the lesion had decreased in size with no fish bone-like structure.


American Journal of Roentgenology | 2013

Extent of Arterial Tumor Enhancement Measured With Preoperative MDCT Gastrography Is a Prognostic Factor in Advanced Gastric Cancer After Curative Resection

Masahiro Komori; Yoshiki Asayama; Nobuhiro Fujita; Kiyohisa Hiraka; Daisuke Tsurumaru; Yoshihiro Kakeji; Hiroshi Honda

OBJECTIVE The objective of this study was to investigate the correlation between pathologic findings and arterial tumor enhancement at MDCT gastrography of patients with a prognosis of advanced gastric cancer after curative resection. MATERIALS AND METHODS The cases of 41 patients with advanced gastric cancer (23 men, 18 women; age range, 35-92 years; median, 60 years) who underwent MDCT gastrography and optical endoscopy before surgery were retrospectively evaluated. Two radiologists reviewed virtual endoscopic and multiplanar reconstruction images to measure arterial phase CT values of the inner tumor margin and healthy gastric wall. They used consensus regions of interest on a cross-sectional image of the largest tumor diameter and then calculated tumor-to-normal wall enhancement ratio (TNR). Advanced gastric cancers were divided into high- and low-TNR groups with mean TNR as the cutoff. The correlations between groups and pathologic factors, patient survival, and mode of recurrence were studied. RESULTS Multivariate logistic regression analysis showed that the arterial tumor enhancement ratio correlated with both microvessel density and lymphatic vessel invasion. The survival rate after curative resection was worse for the high-TNR group than for the low-TNR group. The rate of lymphatic and hematogenous recurrences was also higher in the high-TNR group. Multivariate survival analysis revealed that TNR was an independent prognostic factor. CONCLUSION The extent of arterial tumor enhancement correlated with tumor angiogenesis and lymphatic vessel invasion and was a useful prognostic indicator after curative resection in patients with advanced gastric cancer.


Japanese Journal of Radiology | 2011

Description of early gastric cancer with wall-carving technique on multidetector computed tomography

Satoshi Kawanami; Masahiro Komori; Daisuke Tsurumaru; Shuji Matsuura; Akihiro Nishie; Hiroshi Honda

PurposeWe introduce a new volume-rendering method, named the “wall-carving (WC) technique,” for luminal organs on contrast-enhanced multidetector row computed tomography (MDCT) using a gas-extension protocol. This study aimed to investigate the enhancement profile of the normal gastric wall, particularly focused on the relation between depth and gray value in the normal gastric wall, as a background to distinguish early gastric cancer (EGC) on MDCT.Materials and methodsWe retrospectively evaluated 32 data sets of abdominal CT with EGC. All data sets were obtained with a 64-detector-row CT after administration of an effervescent agent, anticholinergic drug, and intravenous contrast material. The enhancement profile was analyzed in the normal gastric body and antrum (n = 32) by the depth from the air-mucosa interface. We also examined the visual accessibility of the WC image. Institutional review board approval was obtained for this study.ResultsThe profile curve showed that the thickness of the normal gastric wall was 3.75–6.25 mm (mean 4.8 mm), and the maximum enhancement was observed at the layer of 1.875 mm in each case. The enhancement pattern of the EGC was visually accessible, especially at a depth of 1.875–3.75 mm.ConclusionThe enhancement profile showed a peak at the depth within the inner half-thickness of the estimated normal gastric wall. The WC image seems to be a good alternative for detecting tumor enhancement and its relation with the surrounding vascular structures in the gastric wall.


European Journal of Radiology | 2012

Contrast-enhanced MDCT gastrography for detection of early gastric cancer: Initial assessment of “wall-carving image”, a novel volume rendering technique

Masahiro Komori; Satoshi Kawanami; Daisuke Tsurumaru; Shuji Matsuura; Kiyohisa Hiraka; Akihiro Nishie; Hiroshi Honda

OBJECTIVE We developed a new volume rendering technique, the CT gastrography wall carving image (WC) technique, which provides a clear visualization of localized enhanced tumors in the gastric wall. We evaluated the diagnostic performance of the WC as an adjunct to conventional images in detecting early gastric cancer (EGC). MATERIALS AND METHODS Thirty-nine patients with 43 EGCs underwent contrast-enhanced MDCT gastrography for preoperative examination. Two observers independently reviewed the images under three different conditions: term 1, Axial CT; term 2, Axial CT, MPR and VE; and term 3, Axial CT, MPR, VE and WC for the detection of EGC. The accuracy of each condition as reviewed by each of the two observers was evaluated by receiver operating characteristic analysis. Interobserver agreement was calculated using weighted-κ statistics. RESULTS The best diagnostic performance and interobserver agreement were obtained in term 3. The AUCs of the two observers for terms 1, 2, and 3 were 0.63, 0.73, and 0.84, and 0.57, 0.73, and 0.76, respectively. The interobserver agreement improved from fair at term 1 to substantial at term 3. CONCLUSIONS The addition of WC to conventional MDCT display improved the diagnostic accuracy and interobserver reproducibility for the detection of ECG. WC represents a suitable alternative for the visualization of localized enhanced tumors in the gastric wall.


Japanese Journal of Radiology | 2012

A case of rectal Dieulafoy’s lesion successfully treated by transcatheter arterial embolization

Yusuke Nishimuta; Diasuke Tsurumaru; Masahiro Komori; Yoshiki Asayama; Tatsuyuki Ishibashi; Hiroshi Honda

A 50-year-old man showed massive lower gastrointestinal bleeding without a triggering episode. An emergency colonoscopy revealed a protruding vessel in the lower rectum with no active bleeding. No underlying ulcer was seen within the surrounding mucosa. These findings were consistent with rectal Dieulafoy’s lesion. Angiography was requested to identify the source of bleeding and for possible embolization. On the initial angiography, the bleeding point was unclear. Abnormal vessels such as arteriovenous malformation or nidus were not found. He again developed hematochezia, requiring transfusion of red blood cells. However, the second colonoscopy showed no active bleeding from the protruding vessel in the rectum. During the second angiography, sudden bleeding occurred. Angiography showed extravasation of contrast medium from the distal branch of the superior rectal artery. Transcatheter arterial embolization was performed, and was very effective.


Gastroenterology Research and Practice | 2010

Gastric Mucosal Changes Caused by Lugol's Iodine Solution Spray: Endoscopic Features of 64 Cases on Screening Esophagogastroduodenoscopy

Daisuke Tsurumaru; Takashi Utsunomiya; Shuji Matsuura; Masahiro Komori; Satoshi Kawanami; Tatsuyuki Ishibashi; Hiroshi Honda

Aim. To clarify the endoscopic mucosal change of the stomach caused by Lugols iodine solution spray on screening esophagogastroduodenoscopy (EGD). Methods. Sixty-four consecutive patients who underwent EGD for esophageal squamous cell carcinoma screening were included in this study. The records for these patients included gastric mucosa findings before and after Lugols iodine solution was sprayed. The endoscopic findings of the greater curvature of the gastric body were retrospectively analyzed based on the following findings: fold thickening, exudates, ulcers, and hemorrhage. Results. Mucosal changes occurred after Lugols solution spray totally in 51 patients (80%). Fold thickening was observed in all 51 patients (80%), and a reticular pattern of white lines was found on the surface of the thickened gastric folds found in 28 of the patients (44%). Exudates were observed in 6 patients (9%). Conclusion. The gastric mucosa could be affected by Lugols iodine; the most frequent endoscopic finding of this effect is gastric fold thickening, which should not be misdiagnosed as a severe gastric disease.


Radiology Research and Practice | 2013

Role of Barium Esophagography in Patients with Locally Advanced Esophageal Cancer: Evaluation of Response to Neoadjuvant Chemoradiotherapy

Daisuke Tsurumaru; Kiyohisa Hiraka; Masahiro Komori; Yoshiyuki Shioyama; Masaru Morita; Hiroshi Honda

Purpose. This retrospective study examined the usefulness of barium esophagography, focusing on the luminal stenosis, in the response evaluation of neoadjuvant chemoradiotherapy (NACRT) in patients with esophageal cancer. Materials and Methods. Thirty-four patients with primary advanced esophageal cancer (≥T2) who were treated with NACRT before surgical resection were analyzed. All patients underwent barium esophagography before and after NACRT. The tumor length, volume, and percent esophageal stenosis (PES) before and after NACRT were measured. These values and their changes were compared between histopathologic responders (n = 22) and nonresponders (n = 12). Results. Posttreatment tumor length and PES in responders (4.5 cm ± 1.1 and 33.0% ± 18.5) were significantly smaller than those in nonresponders (5.8 cm ± 1.9 and 48.0% ± 12.9) (P = 0.018). Regarding posttherapeutic changes, the decrease in PES in responders (31.5% ± 13.9) was significantly greater than that in nonresponders (14.4% ± 10.7) (P < 0.001). The best decrease in PES cutoff with which to differentiate between responders and nonresponders was 18.8%, which yielded a sensitivity of 91% and a specificity of 75%. Conclusions. Decrease in PES is a good parameter to differentiate responders from nonresponders for NACRT. Barium esophagography is useful in response evaluation to NACRT in patients with locally advanced esophageal cancer.


Japanese Journal of Radiology | 2013

Prediction of intraoperative bleeding during endoscopic treatment in patients with early gastric cancers: utility of contrast-enhanced MDCT gastrography and the wall-carving image technique.

Daisuke Tsurumaru; Satoshi Kawanami; Masahiro Komori; Kiyohisa Hiraka; Yoshiki Asayama; Hiroshi Honda


Japanese journal of clinical radiology | 2012

CT diagnosis of gastric cancers

Daisuke Tsurumaru; Masahiro Komori; K. Uchida; Y. Nishimuta; Y. Asayama; Hiroshi Honda


Japanese journal of clinical radiology | 2012

Spectrum of imaging findings of gastrointestinal lymphoma

Kiyohisa Hiraka; Akihiro Ino; T. Utsunomiya; Masanobu Ueda; M. Horinouchi; Masahiro Komori; Daisuke Tsurumaru; K. Uchida; N. Harada; K. Yasumori; T. Muranaka; Y. Shimoda

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