Detectability of hypervascular small hepatocellular carcinoma by dynamic spiral CT

Thirty-one cases of small hepatocellular carcinoma (HCC) under 3 cm in diameter underwent Spiral CT with bolus injection of contrast medium (Dynamic Spiral CT). Dynamic Spiral CT was compared with CT after intra-arterial injection of iodized oil (Lipiodol-CT). The detectability of 79 nodules of small HCC on early phase images of Dynamic Spiral CT was 49.4% (32.6% for those under 1 cm in diameter, 58.3% for 1-2 cm, 91.7% for 2-3 cm). The detectability of small HCCs above the hilum of the liver was better than that below the hilum. Five lesions were detected only on delayed CT images, but not on early phase CT images. Dynamic Spiral CT is useful for detecting hypervascular small HCCs, and both early phase and delayed CT images must be obtained. (author)