First Department of Internal Medicine, School of Medicine, Fukuoka University
small hepatocellular carcinoma (HCC), Ultrasonography, Echogenisity of HCC, Mosaic pattern, Posterior echo enhancement
Clinical diagnosis and ultrasonic findings of hepatocellular carcinoma (HCC) smaller than 3 cm in diameter were analysed of 61 lesions in 47 patients. Detectability of the lesion by US, CT and Angiography were calculated. Echogenicity of the lesion and frequency of detected ultrasonic findings such as halo, mosaic pattern, posterior echo enhancement and lateral shadows of the lesion were evaluated. Detectability of the lesion smaller than 1 cm in diameter by US, CT and Angiography were 79%, 64% and 69%, respectively. On ultrasonic tomogram, most of the small lesions smaller than 1 cm represented as hypoechoic lesions but larger than 2 cm as isoechoic. Mosaic pattern and posterior echo enhancement were recognized in more than a half of the patients with small HCC. Mosaic pattern and posterior echo enhancement were useful findings for diagnosis of HCC larger than 2 cm in diameter, but these findings were rarely encountered in patients with HCC smaller than 1 cm.