Figure 1.

Classification of B-mode ultrasonographic images of small hepatocellular carcinoma. A-D: Hepatocellular carcinoma nodules < 3 cm in diameter were classified into two groups using B-mode ultrasonography: Type 1 with halo (A) and type 2 without halo. Type 2 was then further categorized into three subgroups: Type 2a, homogenous hyperechoic (B); Type 2b, hypoechoic with smooth margins (C); Type 2c, hypoechoic with irregular or unclear margins (D). Hepatocellular carcinoma nodules are indicated by arrows.