To evaluate the role of two-dimensional ultrasound combined with contrast-enhanced ultrasonography (CEUS) in the classification of liver nodules in cirrhotic patients.

Consecutively cirrhotic patients with intrahepatic nodules at Xixi Hospital of Hangzhou were included from November 2015 to December 2016. All (142 nodules in 109 patiens) presented as non-cancerous focal lesions on conventional magnetic resonance imaging and CT examination and had available information of liver biopsy. Each lesion was percutaneous biopsied under the guidance of two-dimensional ultrasound. Ultrasonographic parameters evaluated were as following: (1) sizes of nodules under US; (2) ultrasonographic characteristics of the nodular; (3) CEUS enhancement features of the nodules. Four types of hepatic nodule suggesting different histology were defined according to the ultrasonographic parameters. χ² test was used to compare the difference of hepatocellular carcinoma (HCC) incidence among liver nodules with varying sizes and nodules with different enhancement features under CEUS. As for the statistical differences of HCC and high-grade dysplastic nodule (HGDN) incidence between type Ⅲ & Ⅳ nodules and type Ⅰ & Ⅱ nodules, χ² test was also used for analysis.

A total of 142 eligible nodules were detected in 109 patients with cirrhosis, including 16 HCCs, 2 intrahepatic cholangiocellular carcinomas (ICC), 41 HGDNs, 40 low-grade dysplastic nodules (LGDN) and 43 regenerative nodules (RN). In terms of diameter, all (6/6) the nodules larger than 2.0 cm, 20.0% (8/40) of middle size nodules (1.5-2.0 cm), were HCCs. The remained 2 lesions of HCC came from two subgroups with even small size nodules [1.0-1.4 cm (n=93), and <1.0 cm (n=3), in diameter], respectively. Two lesions of ICC were attributed to nodules with a 1.0-1.4 cm diameter. About 28 nodules with a diameter of 1.5-2.0 cm, 13 nodules with a diameter of 1.0-1.4 cm were HGDN. HCC incidences between these 4 groups were different significantly (χ²=61.425, P<0.001). As for the CEUS, 14 nodules exhibited a rapid enhancement feature in arterial phase, 12 of which were HCC. In 56 nodules with a slow enhancement feature, 4 nodules were HCC. HCC incidences between these 3 groups were different significantly (χ²=75.752, P<0.001). Under the combined ultrasonography, HCC incidences of type Ⅲ and type IV nodules were significantly higher than that of type Ⅰ and type Ⅱ lesions [21.9% (16/73) vs 0 (0/65), χ²=15.222, P<0.001], similar result was observed in the comparison of HGDN incidences between type Ⅲ & IV and type Ⅰ & Ⅱ nodules[53.4% (39/73) vs 3.1% (2/65), χ²=38.842, P<0.001].

The classification presented by this study, combining the three ultrasonographic parameters, which is nodule size, nodular echo characteristics and enhancement features of the nodules under CEUS, could be helpful for the diagnosis of HCC in cirrhotic patients with ill-defined nodule on routine image examination.