Figure 1. Hepatocellular carcinoma(HCC) (Edmonson grade I) in a 65-year-old man. (a) Baseline ultrasound image shows a hypoechoic HCC nodule in the right lobe of the liver 2.1 cm in diameter. (b) Arterial phase image obtained at 19 s after contrast agent administration shows a homogeneous hyperenhancement of the lesion. (c) Portal phase image obtained at 82 s. The nodule is isoechoic with respect to the surrounding liver. (d) Late portal phase image obtained at 190 s. The HCC is slightly hypoechoic with respect to the surrounding liver.