Gadoxetic acid-enhanced MRI versus multiphase multidetector row computed tomography for evaluating the viable tumor of hepatocellular carcinomas treated with image-guided tumor therapy.

ABSTRACT

PURPOSE: To compare the diagnostic performance of gadoxetic acid-enhanced MRI with that of multi-phase 40- or 64-multidetector row computed tomography (MDCT) to evaluate viable tumors of hepatocellular carcinomas (HCCs) treated with image-guided tumor therapy. MATERIALS AND METHODS: A total of 108 patients with 162 HCCs (56 lesions with viable tumor and 106 without viable tumor) treated by means of transcatheter arterial chemoembolization or radiofrequency ablation were retrospectively included in this study. All patients underwent multi-phase CT at 40- or 64-MDCT and gadoxetic acid-enhanced MRI using 3.0 Tesla (T). Two observers independently and randomly reviewed the CT and MR images of the treated lesions. The diagnostic performance of two techniques for the evaluation of the viable tumors in the treated lesions was assessed with a receiver operating characteristic (ROC) analysis. RESULTS: For each observer, the areas under the ROC curve were 0.953 and 0.969 for MRI, and 0.870 and 0.888 for MDCT (P < 0.05). The diagnostic accuracies (96.3% for each observer) and sensitivities (92.9% and 96.4%) of MRI in two observers were significantly higher than those (82.7% and 80.9%, 53.6% for each observer, respectively) of MDCT (P < 0.001). The negative predictive values (96.3% and 98.1%) of MRI in two observers were significantly higher than those (80.0% and 79.5%) of MDCT (P < 0.001). For each observer, specificities and positive predictive values did not differ significantly between the two techniques (P > 0.05). CONCLUSION: Gadoxetic acid-enhanced MRI shows better diagnostic performance than that of MDCT for evaluating the viable tumors of HCCs treated with image-guided tumor therapy.