Ultrasonography of small hepatic tumors.

The differential accuracy of ultrasonographic examinations of small hepatic tumours was analyzed by receiver-operating characteristics. Using only one image of a single hepatic tumor under 3 cm in diameter as revealed by real-time scanner, the readers were requested to select one out of five diagnoses (hepatocellular carcinoma, metastatic tumor, cavernous hemangioma, cyst, or miscellaneous) and to choose the credibility from five levels of confidence. The averaged diagnostic accuracy was 68% in hepatocellular carcinoma, 70% in metastatic tumor, and 77% in cavernous hemangioma. Hepatic tumors were classified retrospectively into eight ultrasonographic patterns, based on mutual consent. The mosaic and hypoechoic patterns were relatively characteristic of hepatocellular carcinoma (91% and 92% respectively). Except for these two patterns, ultrasonographic findings in small liver tumors were nonspecific, including frequently reported hyperechoic pattern for cavernous hemangioma.