Application of contrast-enhanced ultrasound in differential diagnosis of ≤ 3 cm hepatocellular carcinoma and focal nodular hyperplasia of the liver

ObjectiveTo investigate the diagnosis value of contrast-enhanced ultrasound (CEUS) in the differentiation of hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH) of the liver with ≤3 cm of maximum diameter. MethodsThe image characteristics in 48 lesions of HCC with maximum diameter≤3 cm and 48 lesions of FNH with maximum diameter≤3 cm confirmed by pathology were retrospectively analyzed. The phase changes, enhancement patterns and enhancement characteristics of the lesions in the two groups were compared. ResultsAll lesions in the two groups showed high-echo in the arterial phase. The contrast arrival time in HCC group and FNH group was 17(15, 19) s and 15(12, 18.75) s (P＝0.017); the peak time in the two groups was 21(17, 25) s and 22(19, 26) s (P＞0.05). The main enhancement patterns of HCC group and FNH group in arterial phase were homogeneous enhancement and centrifugal enhancement, respectively. All HCC lesions showed homogeneous enhancement, which was significantly higher than FNH (2.08%, P＜0.05); 97.91% of FHN lesions showed centrifugal enhancement, which was higher that of HCC lesions (0, P＜0.05). During the CEUS process, 87.5% of HCC lesions showed “rapid fill-in and rapid wash-out”, which was significantly higher than that of FNH lesions（8.33%，P＜0.05）; 91.67% of FNH lesions showed “rapid fill-in” and “synchronous/slow wash-out” which was significantly higher than that of HCC lesions （12.50%，P＜0.05）. ConclusionCEUS is helpful in the differential diagnosis of FNH and HCC with maximum diameter≤3 cm．