Contrast-enhanced Doppler ultrasonography in the diagnosis of hepatocellular carcinoma and premalignant lesions in patients with cirrhosis

Hepatocellular carcinogenesis in cirrhosis is a multistage process that inc ludes large regenerative nodules, dysplastic nodules, and hepatocarcinoma. The aim of this study was to establish whether contrast-enhanced Doppler ul trasonography (US) is able to distinguish between early hepatocellular carc inoma (HCC) and small nonmalignant nodules in cirrhosis. Between January 19 98 and December 1999, 500 cirrhotic patients with no previous history of HC C or evidence of hepatic focal lesions were enrolled and prospectively foll owed-up with US every 6 months until December 2000. Sixty-one patients deve loped focal lesions, 12 multifocal, and 49 monofocal. Biopsy of focal lesio ns, contrast-enhanced Doppler US, and spiral computed tomography (CT) were performed in 41 consecutive patients with small (<3 cm) monofocal lesions. Twenty nodules were diagnosed as HCC and 21 as nonmalignant (14 large regen erative nodules, 3 low-grade, and 4 high-grade dysplastic nodules) by liver biopsy. Intratumoral arterial blood flow was detected in 19 of 20 (95%) HC C and 6 of 21 (28%) nonmalignant nodules by contrast-enhanced Doppler US (P <.0001). The mean peak resistance and pulsatility indices were 0.82 +/- 0.0 9 and 1.56 +/- 0.2 in HCC and 0.62 +/- 0.08 and 0.82 +/- 0.08 in dysplastic lesions (P =.002 and .0001), respectively. Spiral CT revealed arterial per fusion in 19 of 20 HCC and in 4 of 21 nonmalignant nodules (high-grade dysp lastic nodules). Four of the apparently false-positive nodules at enhanced Doppler US were high-grade dysplastic nodules and 2 evolved to HCC during f ollow-up. In conclusion, contrast-enhanced Doppler US is a noninvasive, ver y sensitive technique in differentiating malignant and premalignant lesions from nonmalignant focal lesions in the liver.