COMPARISON BETWEEN CONVENTIONAL AND SPIRAL CT IN PATIENTS WITH HYPERVASCULAR HEPATOCELLULAR-CARCINOMA

To determine the usefulness of spiral CT in the detection of hypervasc ular hepatic lesions, we compared conventional contrast enhanced CT (C ECT) with whole liver dynamic scanning during the artery-dominant phas e by spiral CT (SDCT), using hypervascular hepatocellular carcinoma (H CC) as a model. Twenty-nine patients with 56 hypervascular nodular typ e HCCs detected by hepatic digital subtraction angiography were examin ed by both CT techniques. These nodular type HCCs were divided into th ree groups according to diameter: < 10 mm (n = 7), 10-20 mm (n = 17), and over 20 mm (n = 32). None of seven lesions less than 10 mm in diam eter was seen by either technique. Of 17 lesions 10-20 mm in diameter, four (24%) were detected by precontrast CT plus CECT, whereas 14 (82% ) were detected by precontrast CT plus SDCT. There were no lesions det ected by CECT only, whereas 10 lesions were detected by SDCT only (P < 0.01 by signed test). For 32 lesions over 20 mm in diameter, there wa s no significant difference in detection rates between the CT techniqu es. Our results indicate that spiral CT is useful for the detection of relatively small hypervascular hepatic lesions such as hypervascular HCCs.