MR imaging of hepatocellular carcinoma.

MR imaging is useful in the diagnosis and early detection of HCC. Characteristic findings for overt HCC, a pseudocapsule and an intratumoral mosaic pattern, are better demonstrated on MR imaging than by other imaging modalities such as ultrasound and CT scanning. Signal intensity on T2-weighted images is useful in evaluating the grade of malignancy of hepatocytic nodular lesions. Hyperintensity on T1-weighted MR imaging is almost always seen in precancerous hepatocellular lesions and in about one third of overt HCC tumors, whereas other hepatic tumors show hypointensity on T1-weighted MR imaging. In evaluating tumor vascularity, gadolinium-enhanced dynamic MR imaging is an essential and powerful tool.