Assessment of vascularity in hepatic tumors:: Comparison of power Doppler sonography and intraarterial CO2-enhanced sonography

OBJECTIVE. The purpose of the study was to compare power Doppler sonography with intraarterial CO2-enhanced sonography for revealing vascularity in treated and untreated hepatic tumors. SUBJECTS AND METHODS. Fifty-five patients with 93 liver tumors were prospectively examined with power Doppler sonography and CO2-enhanced sonography. These tumors included 29 hepatocellular carcinomas in patients with no previous treatment, 26 treated hepatocellular carcinomas, and 38 hemangiomas. The vascular depiction of power Doppler sonography was compared with that obtained in the early phase of CO2-enhanced sonography. The results of angiography were also recorded for comparison. RESULTS. In the hepatocellular carcinomas, power Doppler sonography was the same as CO2-enhanced sonography in 18 (62%) of 29 tumors, was inferior to CO2-enhanced sonography in nine (31%) of 29 tumors, and was superior to CO2-enhanced sonography in two (7%) of 29 rumors. In the treated hepatocellular carcinomas, power Doppler sonography was the same as CO2-enhanced sonography in 15 (58%) of 26 tumors and was inferior in 11 (42%) of 26 tumors. In hemangiomas, the same vascularity was found in both studies in 15 (39%) of 38 tumors, CO2-enhanced sonography was superior in 22 (58%) of 38 tumors, and power Doppler sonography was superior in one (3%) of 38 rumors. As a whole, 45% of the 93 rumors showed better vascular depiction on CO2-enhanced sonography. However, 19.4% of tumors were hypovascular using power Doppler sonography but hypervascular using CO2-enhanced sonography. CONCLUSION. Power Doppler sonography is a useful technique for screening hepatic tumor vascularity. CO2-enhanced sonography is superior to power Doppler sonography in depicting tumor vascularity in treated hepatocellular carcinomas and in hemangiomas, especially small hemangiomas.