Objective: To compare the enhancement features of dysplastic nodules with a focus of hepatocellular carcinoma (DN-HCC) versus HCC and regenerative nodules (RN) in cirrhotic patients.

Methods: One hundred and ninety-three cirrhotic patients were enrolled in this study; they had 215 focal liver lesions, 1.0-3.5 cm in size, which were examined using contrast-enhanced ultrasound (CEUS) with SonoVue^® and diagnosed as HCC, RN or DN-HCC by biopsy. Samples were obtained using 18-gauge needles in the different enhanced areas. The enhancement features of DN-HCC, HCC and RN were evaluated.

Results: There were 86 HCC lesions, 102 RN lesions, and 27 DN-HCC lesions diagnosed by biopsy. Of 86 HCC lesions, 87.2% (75/86) showed complete enhancement during the arterial phase, and 12.8% (11/86) had inhomogeneous enhancement, with no enhancement in the central area during the arterial phase; 100% (86/86) exhibited washout during the late phase. Of 102 RN lesions, 95.1% (97/102) had delayed or simultaneous enhancement during the arterial phase, and 4.9% (5/102) displayed slight enhancement during the arterial phase; 26.5% (27/102) exhibited washout and 73.5% (75/102) exhibited no washout during the late phase. In 27 DN-HCC lesions, only part of the lesions enhanced during the arterial phase and washed out during the late phase; the other areas had delayed or simultaneous enhancement during the arterial phase, and 29.6% (8/27) exhibited slight washout in the late phase. In 86 HCCs, the pathological feature was HCC in the enhanced area of 75 lesions, hepatocellular fatty degeneration in the slightly enhanced area of 7 lesions, and hepatocellular necrosis in the unenhanced area and HCC in the enhanced area of 4 lesions. In 102 RNs, the pathological diagnosis was hepatocyte proliferation with or without fatty degeneration. In 27 DN-HCCs, the pathological feature was HCC in the enhanced area and hepatocyte regeneration in the unenhanced area.

Conclusions: CEUS is useful for the diagnosis of focal liver lesions in cirrhotic patients. CEUS can help determine the progression from RN to DN-HCC to HCC by analyzing the hemodynamics. CEUS can promote the diagnostic accuracy of a biopsy by providing more accurate information on the site of the biopsy.