Hepatic hemangioma: Quantitative color power US angiography - Facts and fallacies

PURPOSE: To explore the origin of signals: detected with color power ultrasound (US) angiography (CPA) and evaluate a semiquantitative method to assess signals in hepatic hemangiomas. MATERIALS AND METHODS: Twenty-four adult patients with 27 hepatic hemangiomas (<2 cm in diameter) and five patients with five hyperchoic hepatic metastases underwent CPA and conventional color Doppler US in this prospective study. A sponge phantom was-studied to determine whether the origin of CPA signals was related to architecture. The mean number of signals and the signal density in each lesion were scored. RESULTS: A "diffuse blush" was seen in all capillary-hemangiomas at CPA, whereas no signal was seen at color Doppler US. The sponge phantom test produced a CPA : appearance similar-to that of capillary hemangiomas. :Quantitative analysis of CPA: images of hepatic hemangiomas showed a mean of 16.1 signals per cubic centimeter and a mean signal area of 25%. Hyperechoic avascular hepatic metastases resulted in CPA images similar to those of hepatic :hemangiomas, with no quantitative difference in signal count, despite-a mild qualitative difference at CPA. CONCLUSION: CPA signals in hepatic hemangiomas appear to be related more to, architecture than to true capillary flow. There is a qualitative difference in the strength of the blush at CPA between hepatic hemangiomas and metastases, which may be-the only possible differentiating factor.