[Application of CO2 enhanced ultrasound for two-stage operation of hepatic tumors]

The feasibility of CO2 enhanced ultrasound (CO2-EUS) was evaluated in two-stage operation patients with hepatic tumors. CO2-EUS was carried out in nine patients with indwelling catheter within hepatic artery for two-stage operation of liver cancer. CO2 microbubbles mixing by 5 ml of 5% NaHCO3 and 2.5 ml of 5% Vitamine C were injected into the indwelling catheter. The computed sonography of ACUSON 128XP/10 with a 3.5 MHz convex transducer was used for this study. The enhanced parenchyma of the liver obtained by CO2-EUS and the lasting time of enhancement was about 8 minutes. The hepatic tumors, after chemotherapeutic treatment via indwelling catheter, were variously enhanced by CO2 microbubbles. The enhanced sonogram of the tumors took the forms of hypoechoic, ring-like, or spotty enhanced pattern lasting for more than 30 minutes. The margin of the enhanced tumors was very clear in CO2-EUS. CO2-EUS detected five more lesions (size 1-3 cm) besides 9 lesions by conventional ultrasound. CO2-EUS was extremely useful in evaluating curative effects of tumor, increasing detection rates of small tumor, and improving thoroughness of two-stage operation.