Assessment of tumor vascularity in hepatocellular carcinoma: Comparison of power Doppler US and color Doppler US

PURPOSE: To compare power Doppler ultrasound (US) with conventional color Doppler US for the assessment of tumor vascularity in hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Fifty-one patients with 88 histologically proved HCCs were examined with power and color Doppler US according to a standardized examination protocol. Findings at Doppler studies of each lesion were correlated with findings at digital subtraction angiography. RESULTS: Angiography revealed neovascularization or staining in 75 (85%) of 88 lesions. Intratumoral color signals with an arterial Doppler spectrum were detected in 69 (92%) of 75 angiographically hypervascular tumors at power Doppler US and in 55 (73%) of 75 at color Doppler US (P <.01). Blood flow signals with an arterial Doppler spectrum were not detected at power or color Doppler US in any of the 13 angiographically hypovascular tumors. The small size and the deep location of the lesion significantly reduced (P <.05) the detection rate of blood flow signals at color Doppler US but did not affect the results of power Doppler US. CONCLUSION: Power Doppler US is superior to conventional color Doppler imaging in the depiction of tumor vascularity in HCC.