Diagnostic Performance of Multidetector Row Computed Tomography, Superparamagnetic Iron Oxide-Enhanced Magnetic Resonance Imaging, and Dual-Contrast Magnetic Resonance Imaging in Predicting the Appropriateness of a Transplant Recipient Based on Milan Criteria Correlation With Histopathological Findings

Purpose: To retrospectively evaluate the diagnostic performance of multidetector row CT (MDCT), superparamagnetic iron oxide (SPIO)-enhanced MRI (S-MRI), and dual-contrast MRI (DC-MRI) in predicting the appropriateness of recipients with hepatocellular carcinoma (HCC) for liver transplantation (LT), based on Milan criteria. Materials and Methods: This retrospective study received Institutional Review Board approval. Requirement for patient informed consent was waived. During a 3-year period, 80 patients who underwent LT were enrolled in this study. However, 2 patients in whom >10 HCCs were present were excluded from the analysis of detection performance of imaging modalities for HCC. MDCT and DC-MRI examinations with the sequential use of SPIO and gadolinium were performed in all patients. Interval readings for MDCT, S-MRI, and DC-MRI were performed. Two radiologists independently recorded confidence levels using a 4- and 5-point scale for the presence of HCC and for the appropriateness regarding LT, respectively. Image interpretation was compared with histopathological results on a lesion-by-lesion basis. Diagnostic performance of the 3 imaging techniques was compared using jackknife alternative free-response receiver operating characteristic and ROC analyses. Results: Eighty-two HCCs were detected in 38 of 78 patients. Twenty-seven HCCs were larger than 2 cm in diameter and 55 HCCs were smaller than 2 cm in diameter. Among 80 patients included for the assessment of eligibility for LT, 69 recipients were categorized as appropriate and the remaining I I patients were found to be inappropriate for LT based on Milan criteria. In terms of detecting HCCs, the reader-averaged figure of merit was highest for DC-MRI (0.764), followed by S-MRI (0.702) and MDCT (0.672). The use of DC-MRI was significantly better than the use of the other 2 modalities specifically for HCCs smaller than 2 cm in diameter (P < 0.001) although not for those larger than or equal to 2 em (P = 0.125-1). The A, value for predicting the appropriateness for LT was highest with the use of S-MRI (0.841), followed by the use of DC-MRI (0.830) and the use of MDCT (0.790). However, significant differences were not seen for the predictions determined by both radiologists (P = 0.384-1). This result might be because of the small number of patients who had a critical number of HCCs (ie, 2 similar to 4 HCCs). Conclusion: DC-MRI showed significantly better diagnostic performance in transplantation candidates for the detection of HCCs, particularly small HCCs, than both MDCT and S-MRI. However, for assessing the appropriateness of a transplantation recipient based on Milan criteria, MDCT, S-MRI, and DC-MRI showed comparable diagnostic accuracy without a statistical difference.