HEPATIC TUMOR INVASION OF FILE DUCTS - WEDGE-SHAPED SIGN ON MR-IMAGES

PURPOSE: To clarify the diagnostic importance of wedge-shaped areas of increased signal intensity that surround liver tumors on T1-weighted magnetic resonance (MR) images. MATERIALS AND METHODS: In five patient s with hepatic tumors, T1-weighted MR images that demonstrated wedge-s haped areas of increased signal intensity in the liver were reviewed; findings were compared with those at surgical and histologic examinati ons. RESULTS: MR images showed localized intrahepatic bile duct dilata tion lateral (three patients) and medial (two patients) to liver tumor s within the wedge-shaped areas. At histopathologic examination, intra ductal tumor growth was seen in local bile ducts in the same areas in five patients, and lipofuscin deposits were seen in the cytoplasm of a trophic hepatocytes in three patients. CONCLUSION: On T1-weighted imag es, wedge-shaped areas of increased signal intensity associated with l iver tumors indicate intraductal tumor extension in intrahepatic bile ducts. T1 shortening is possibly caused by lipofuscin deposits in atro phic hepatocytes.