SMALL HEPATOCELLULAR-CARCINOMA IN PATIENTS WITH CHRONIC LIVER-DAMAGE - PROSPECTIVE COMPARISON OF DETECTION WITH DYNAMIC MR-IMAGING AND HELICAL CT OF THE WHOLE LIVER

PURPOSE: To compare contrast material-enhanced dynamic magnetic resona nce (MR) imaging with helical computed tomography (CT) for the detecti on of small hepatocellular carcinoma (HCC) in patients with chronic li ver damage. MATERIALS AND METHODS: Fifty patients with chronic hepatit is or liver cirrhosis underwent dynamic contrast-enhanced fast low-ang le shot MR imaging and multiple-phase helical CT. Arterial, portal-ven ous, and delayed-phase images were compared. Diagnostic ability with b oth techniques was evaluated by means of receiver operating characteri stic (ROC) analysis; images in patients with (n = 27) and those withou t (n = 15) HCC in whom the same anatomic levels were available for bot h examinations were assessed. Seventy-two lesions were evaluated, and tumor diameter ranged from 0.5 to 3.0 cm (mean, 1.9 cm). RESULTS: ROC analysis showed that the arterial-phase images obtained with both tech niques allowed better detection of HCC. Diagnostic ability was signifi cantly better with arterial-phase MR imaging (mean area under the ROC curve [Az] = 0.96) than arterial-phase CT (Az = 0.87) or with images f rom any other phase (P < .05). For the delayed phase, diagnostic capab ility was significantly better with CT (Az = 0.84) than with MR imagin g (Az = 0.77) (P < .05). CONCLUSION: Arterial-phase dynamic MR imaging is superior to helical CT for the detection of HCC in patients with c hronic liver damage.