Kunihiro Maruyama

Efficacy of gastric blood supply redistribution by transarterial embolization: Preoperative procedure to prevent postoperative anastomotic leaks following esophagoplasty for esophageal carcinoma

Purpose: The aim of this study was to evaluate the effect of preoperative redistribution of gastric blood supply on the prevention of anastomotic leakage following surgical reconstruction of the esophagus.Methods: In 37 patients with esophageal carcinoma, transarterial embolization (TAE) of the left gastric, right gastric, and splenic arteries was preoperatively performed with coils so that gastric blood supply was dependent only on the right gastroepiploic artery.Results: In 34 of 37 patients, preoperative redistribution was successfully performed. The gastric tissue blood flow (TBF) of a gastric tube was higher than in 12 nonredistributed patients. Reduction in the gastric TBF during preparation of a gastric tube was 27.5% in successful patients, in contrast to 68.9% in 12 nonredistributed patients (p<0.005).Conclusion: Preoperative redistribution by TAE reduced the drop in gastric TBF during preparation of a gastric tube and helped prevent postoperative anastomotic leakage in esophageal reconstruction.

Accuracy of plastic replica of aortic aneurysm using 3D-CT data for transluminal stent-grafting: experimental and clinical evaluation.

Purpose To plan stent-grafting for aortic aneurysms with complicated morphology, we prepared life-sized aortic replicas by laser stereolithography using helical 3D-CT data. The accuracy of the replica was evaluated by measurement of vessel phantoms and clinical 3D-CT data. Method An imaginary aortic wall was created from helical CT images of the aorta, and a hollow plastic replica was produced by laser stereolithography. The accuracy of the replica was evaluated in five abdominal aortic aneurysms by experimental phantom studies and measurements of the replicas. Results The mean difference in measurements between 3D-CT images and model vessels and between 3D-CT images and aortic replicas was 0.2 mm each. Therefore, the difference in measurements between real aortic aneurysms and the replicas was at most 0.4 mm. Conclusion The accuracy of the replica is satisfactory, making it useful for preoperative evaluation and simulation for stent-grafting.

Dilatation of Stent-Grafts by Luminal Pressures: Experimental Evaluation of Polytetrafluoroethylene (PTFE) and Woven Polyester Grafts

PurposeTo evaluate the effect on dilatation of three types of covering materials used for endovascular stent-grafts.MethodsStent-grafts with three types of covering material [0.1-mm polytetrafluoroethylene (PTFE), 0.2-mm PTFE, and 0.15-mm woven polyester] were placed in a fluid circuit. For the pulsatile pressure test, the luminal pressure of 190/130 mmHg was loaded up to 300,000 pulses. For the static pressure test, the luminal pressure was increased from 50 to 300 mmHg at 50-mmHg increments. The percent of dilatation of each stent-graft was compared.ResultsThe 0.1-mm PTFE stent-graft was significantly more dilated than the 0.2-mm PTFE and the 0.15-mm woven polyester stent-graft (p < 0.005) in both examinations. There was no significant difference between the 0.2-mm PTFE and the 0.15-mm woven polyester stent-grafts. The dilatation of the 0.1-mm PTFE stent-graft was irreversible.ConclusionThe 0.15-mm woven polyester and the 0.2-mm PTFE stent-grafts may be preferable to the 0.1-mm PTFE stent-graft with regard to dilatation and deformity.

Radiologic diagnosis of pancreatic carcinoma

Radiological diagnostic techniques for the evaluation of pancreatic duct cell adenocarcinoma and their findings are discussed. Pancreatic carcinoma may demonstrate one or more of these diagnostic signs: focal enlargement or deformity, density changes, obliteration and dilatation of the pancreatic and/or biliary duct, local invasion, and metastases. Ultrasonography is commonly used as a screening examination. The presence of pancreatic carcinoma may best be evaluated by dynamic computed tomography (CT) or dynamic magnetic resonance (MR) imaging with administration of intravenous contrast material. Both CT and MR imaging are used for the preoperative assessment of local invasion and vascular involvement. MR cholangiopancreatography (MRCP) allows noninvasive three-dimensional delineation of the pancreatic and biliary duct systems. Angiography may demonstrate vascular involvement questionable on noninvasive examinations. In the near future, the value and efficacy of MR imaging in the diagnosis of small pancreatic carcinoma need to be assessed in comparison with CT and endoscopic studies.

RGSS-ID: An approach to new radiologic reporting system

RGSS-ID is a developmental computer system that applies artificial intelligence (AI) methods to a reporting system. The representation scheme called Generalized Finding Representation (GFR) is proposed to bridge the gap between natural language expressions in the radiology report and AI methods. The entry process of RGSS-ID is made mainly by selecting items; our system allows a radiologist to compose a sentence which can be completely parsed by the computer. Further RGSS-ID encodes findings into the expression corresponding to GFR, and stores this expression into the knowledge data base. The final printed report is made in the natural language.