Small hepatocellular carcinoma: differentiation from adenomatous hyperplastic nodule with color Doppler flow imaging.

Liver nodules smaller than 25 mm in diameter (19 hepatocellular carcinomas [HCCs] and nine adenomatous hyperplastic nodules [AHNs]) were examined with color Doppler flow imaging and hepatic angiography. Angiography revealed a tumor vessel in eight (42%) of the 19 HCCs, while color Doppler flow imaging revealed an arterial pulsating afferent tumor vessel in 10 (53%) of the 19 HCCs but in none of the AHNs. In addition, color Doppler flow imaging revealed a constant-flow efferent tumor vessel continuing to a portal branch in 10 (53%) of the 19 HCCs but in none of the AHNs. In 15 (79%) of the 19 HCCs, a pulsating afferent tumor vessel or a constant-flow efferent tumor vessel or both were observed. Therefore, in this series, color Doppler flow imaging was of value in distinguishing between these two lesions.