Intravenous contrast-enhanced Doppler sonography and intra-arterial carbon dioxide-enhanced sonography in the assessment of hepatocellular carcinoma vascularity before and after treatment

Purpose: To compare i.v. contrast-enhanced sonography (CEUS), power Doppler sonography (PDUS) and i.a. carbon dioxide-enhanced sonography (CO2 US) in assessing hepatocellular carcinoma (HCC) vascularities before and after treatment. Differences between PDUS and CEUS with the aid of CO2 US were also observed. Material and Methods: In all, 43 patients with 67 histologically proved HCCs were examined with PDUS, CEUS, and CO2 US. Among these tumors, 36 were HCCs before treatment and 31 were HCCs treated by transcatheter arterial chemoembolization or percutaneous ethanol injection or a combination of these two treatments. CO2 US was used as the gold standard when comparing the PDUS and CEUS. Results: Of the 36 untreated HCC tumors, 20 (55.6%) were hypervascular compared with the liver parenchyma at PDUS, 28 (77.8%) at CEUS, 31 (86.1%) at the early phase of CO2 US and 32 (88.9%) at the late phase of CO2 US. Of the 31 post-treatment HCCs, 11 (35.5%) showed hypervascularity at PDUS, 25 (80.6%) at CEUS, 25 (80.6%) at the early phase of CO2 US and 26 (83.9%) at the late phase of CO2 US. Conclusion: CO2 US was superior to CEUS and CEUS was superior to PDUS for the detection of tumor vascularity in both untreated and treated HCCs. The duration of enhancement at CEUS was shorter than at CO2 US. The ability of CO2 US to detect additional small tumors was not possible with PDUS and CEUS.