[Doppler sonography in the diagnosis of liver tumors]

The value of color duplex Doppler sonography in evaluating tumor vascularity was investigated in 82 hepatic tumors (61 hepatocellular carcinomas, 11 metastatic cancers, eight adenomatous hyperplasia, one focal nodular hyperplasia, and one cholangiocellular carcinoma) receiving angiography, 64 intrahepatic arteries, and five hepatic cysts. The minimum diameter of the intrahepatic arteries (lateral inferior subsegmental arteries) from which signals could be weakly obtained by using a 3.5 MHz transducer was 0.7 mm. Twenty-eight (74%) of 38 tumors with signals within them had definite tumor vessels on angiography, and continuous blood flow within the tumors showed an association with the dilated tumor vessels. Eighteen (69%) of 26 tumors with signals within them receiving conventional angiography had tumor vessels greater than 0.7 mm. However, only 17 (31%) of 55 tumors less than or equal to 3 cm showed signals within them in contrast to 21 (78%) of 27 tumors greater than 3 cm. Three of eight adenomatous hyperplasias, which were angiographically undetected and had portal or hepatic venous branches, showed signals within them. Four tumors that had abnormally high velocity arterial signals (greater than 0.63 m/sec) within them showed no arteriovenous shunt. Evaluation of tumor vascularity according to the Doppler sonographic findings at the periphery of the tumor was difficult. This was attributed to the fact that the real sample volume was larger than that on B-mode image, with no correlation seen between the signals at the tumor periphery or the existence of arteries surrounding the tumor and tumor vascularity. Although a correlation was seen between tumor vascularity or tumor size and peak systolic velocity determined at the tumor periphery (p less than 0.05), five of six tumors with abnormally high velocities (greater than 0.63 m/sec) at the tumor periphery were greater than or equal to 5 cm in diameter. Doppler signals of the artery feeding the arteriovenous shunt were characterized by abnormally high velocity and low resistive index. In conclusion, Doppler sonography is somewhat useful in evaluating tumor vascularity, but less so in small hepatic tumors.