Diagnosis of recurrent HCC: intraindividual comparison of gadoxetic acid MRI and extracellular contrast-enhanced MRI.

Purpose: To compare the efficacy of magnetic resonance imaging (MRI) with hepatobiliary agents (HBA-MRI) and MRI with extracellular contrast agents (ECA-MRI) for detection of recurrent hepatocellular carcinoma (HCC) after multiple treatments.
Methods: The institutional review board approved this retrospective study and waived the requirement for informed patient consent. A total of 135 patients with suspected HCC recurrence after 2-5 treatments (surgery, transarterial chemoembolization, and/or radiofrequency ablation) underwent both HBA-MRI and ECA-MRI within a 1 month interval. HBA-MRI and ECA-MRI were analyzed for HCC detection by two observers using a five-point scale. The diagnostic performances according to MRI modality were compared.
Results: A total of 136 liver lesions (121 HCCs and 15 benign lesions; median size, 1.9 cm) were identified. ECA-MRI showed greater sensitivity (90.9% vs. 76.9% for observer 1; 91.7% vs. 78.5% for observer 2) and accuracy (91.2% vs. 78.7% for observer 1; 91.9% vs. 80.2% for observer 2) than HBA-MRI for both observers (P = 0.002, 0.003). Fifteen (12.4%) HCCs were correctly diagnosed with ECA-MRI but not with HBA-MRI by both observers. Interobserver agreement was excellent (0.885) for ECA-MRI and substantial (0.749) for HBA-MRI.
Conclusions: For detection of recurrent HCC, ECA-MRI was superior to HBA-MRI in terms of sensitivity and accuracy. Therefore, ECA-MRI could be the preferred imaging modality over HBA-MRI for assessing HCC recurrence following multiple treatments.