Color Doppler flow imaging of liver tumors.

A differential diagnosis of liver tumors was attempted on the basis of the pattern of blood flow within and around tumors on color Doppler flow images. The study comprised 35 patients with liver mass lesions: 20 patients had hepatocellular carcinoma, six had hemangiomas, four had metastatic liver cancers, one had cholangiocellular carcinoma, one had focal fatty liver, and three had liver cysts. A basket pattern (a fine blood-flow network surrounding the tumor nodule) was observed in 15 (75%) of the 20 hepatocellular carcinomas. An image of vessels within the tumor (blood flow that runs into and branches within the tumor) was observed in 13 (65%) of the 20 hepatocellular carcinomas. These two findings were observed only in hepatocellular carcinomas; even when the tumor was smaller than 2 cm in diameter, these findings were observed frequently. In the patients with multiple hepatic metastases, a "detour" pattern (a dilated portal vein meandering around the tumor nodules) was observed. In three of the six hemangiomas, a "spot" pattern (color-stained dots or patches in the central region of the tumor) was seen. Our experience suggests that hepatocellular carcinomas have a characteristic appearance on color Doppler flow images.