Computed tomography of portal vein thrombosis: unusual appearances and pitfalls in diagnosis.

In a review of 25 cases examined by CT in whom the diagnosis of visceral vein thrombosis had been made, we encountered four cases in which problematic CT findings led to an error in diagnosis by the prospective interpreter. In one case, gas in collateral periportal veins mimicked an abscess; in one case, segmentally occluded portal veins resembled dilated bile ducts; and in one case, expansion of the inferior mesenteric vein was interpreted as a pancreatic pseudocyst. One additional case of multiple intrahepatic stones mimicked calcified portal vein thrombus. Although most cases are straightforward, there is a spectrum of findings in visceral vein thrombosis that may lead to confusion; alternative imaging techniques may be necessary in these situations.