Sonographic features of portal vein thrombosis.

The ability of real-time sonography to demonstrate the liver venous network is well documented. Sonographic features of 21 cases of unsuspected portal vein thrombosis, detected by a screening sonography of the upper abdomen and subsequently confirmed by computed tomography, angiography, or surgery, are discussed. Sonographic features of portal vein thrombosis were an echogenic thrombus within the lumen of the vein (67%), demonstration of portal vein collateral circulation (48%), enlargement of the thrombosed segment of the vein (38%), and the so-called cavernomatous transformation of the portal vein (19%). Echogenic endoluminal thrombi were observed with the same incidences in malignant and benign disease. Sonography, unlike angiography, was unable to characterize neoplastic thrombi; only the combination of an echogenic thrombus and an adjacent hepatic mass was strongly suggestive of malignancy, especially hepatoma. The extensive use of sonography as a screening test in upper abdomen pathology will probably improve the detection of portal vein thrombosis, a diagnosis until now considered rare.