Small hepatocellular carcinoma in patients with chronic liver damage: prospective comparison of detection with dynamic MR imaging and helical CT of the whole liver.

Abstract

To compare contrast material-enhanced dynamic magnetic resonance (MR) imaging with helical computed tomography (CT) for the detection of small hepatocellular carcinoma (HCC) in patients with chronic liver damage. Fifty patients with chronic hepatitis or liver cirrhosis underwent dynamic contrast-enhanced fast low-angle shot MR imaging and multiple-phase helical CT. Arterial, portal-venous, and delayed-phase images were compared. Diagnostic ability with both techniques was evaluated by means of receiver operating characteristic (ROC) analysis; images in patients with (n = 27) and those without (n = 15) HCC in whom the same anatomic levels were available for both examinations were assessed. Seventy-two lesions were evaluated, and tumor diameter ranged from 0.5 to 3.0 cm (mean, 1.9 cm). ROC analysis showed that the arterial-phase images obtained with both techniques allowed better detection of HCC. Diagnostic ability was significantly 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 from any other phase (P < .05). For the delayed phase, diagnostic capability was significantly better with CT (Az = 0.84) than with MR imaging (Az = 0.77) (P < .05). Arterial-phase dynamic MR imaging is superior to helical CT for the detection of HCC in patients with chronic liver damage.