Contrast-enhanced intraoperative ultrasonography of small hepatocellular carcinomas.

Nine patients with small hepatocellular carcinomas, ranging up to 2 cm in size (phi: 1.7 +/- 0.2 cm, mean +/- SD), have been encountered, and in two of these patients the cancer was not identifiable by intraoperative ultrasonography. Thus to achieve a better detection of such small hepatic cancers, enhanced intraoperative ultrasonography was tested. Detection by enhanced intraoperative ultrasonography proved successful in all cases. These preliminary results indicate the potential of carbon dioxide as a contrast agent to enhance intraoperative visualization of small liver cancers.