[Computed tomographic detection of air in the portal vein--a case report].

Two cases of portal venous gas (PVG) are presented. One case due to bowel infarction and another due to duodenal ulcer perforation complicated by a subphrenic abscess. The diagnosis was suggested from plain abdominal radiographs and confirmed by unenhanced computed tomography (CT) of the abdomen which is superior to demonstrate gas in the portal venous system. The distinction between PVG and biliary gas is briefly discussed.