MR imaging of hepatocellular carcinomas with biliary tumor thrombi.

We retrospectively evaluate the MR imaging findings of hepatocellular carcinomas (HCC) with biliary tumor thrombi. MR imaging was performed on six patients presenting with obstructive jaundice and/or biliary hemorrhage. T1-weighted images, T2-weighted images, MR cholangiopancreatography (MRCP), and dynamic MR images were obtained. Duodenal endoscopy was performed on all cases and hepatic resection on two cases. HCCs were 1.8-10 cm in diameter (mean 5.8 cm). Biliary tumor thrombi were detected in all patients on MR imaging. Tumor thrombi showed hypointensity on T1-weighted images, hyperintensity on T2-weighted images, and contrast enhancement on the early phase of dynamic MR images. MRCP showed intrahepatic bile duct dilatation in all cases. Biliary hemorrhage was clearly depicted by MR images in five cases and showed hyperintensity on T1-weighted images and hyperintensity or hypointensity on T2-weighted images. Biliary hemorrhage was confirmed by endoscopy in two cases. Portal vein thrombi were also associated in five of six patients. Pathologically, tumor thrombi of HCCs were demonstrated in two patients who underwent hepatic resection. In conclusion, MR imaging is useful for the diagnosis of biliary tumor thrombi from HCC and for evaluating the extension of thrombi and biliary hemorrhage.