The combination of the arterial- and late-phase imagings was best for detecting HCC nodules.

Nearly half of small hepatic nodules detected with ultrasonography were nonHCC nodules. Ultrasonographic findings may not be reliable in characterizing small hepatic nodules in cirrhosis. CT and MR imaging obtained with the various techniques are still insensitive to these hepatic nodules.

Two rare cases of small intrahepatic cholangiocarcinoma with marked hypervascularity are reported. Dynamic computed tomographic and magnetic resonance images of the two cases revealed strong enhancement of the whole tumor on the early phase and prolonged enhancement on the late and delayed phases. In both cases, the tumors turned out to be well-differentiated tubular cholangiocarcinoma that contained a large number of tumor cells and few interstitial fibrous tissues. These results suggest that some intrahepatic cholangiocarcinoma should be differentiated from other hypervascular hepatic tumors, especially hepatocellular carcinoma, and that prolonged enhancement of the tumor on late and delayed phases of dynamic images could be of diagnostic value.

For detecting small hypervascular HCCs, helical CT with i.a. contrast enhancement is superior to helical CT and MR imaging with i.v. enhancement.

We report two cases of angiomyolipoma of the liver, where small amounts of fat on computed tomography, magnetic resonance imaging, and angiography made distinguishing this tumor from other hypervascular tumors difficult. Recognizing the imaging features of no capsule, hypervascularity of the tumor including the fat component, and early venous drainage may be helpful for correctly diagnosing angiomyolipoma of the liver.