Hepatic hemangioma: quantitative color power US angiography--facts and fallacies.

Abstract

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. Twenty-four adult patients with 27 hepatic hemangiomas (< 2 cm in diameter) and five patients with five hyperechoic 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. 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. 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.