Comparison of the current guidelines for diagnosing hepatocellular carcinoma using gadoxetic acid-enhanced magnetic resonance imaging.

OBJECTIVES: To compare the performance of current guidelines applicable to the diagnosis of hepatocellular carcinomas (HCCs) using gadoxetic acid-enhanced magnetic resonance imaging (MRI). METHODS: Two hundred and forty-one hepatic lesions (149 HCCs, six other malignancies, 86 benign lesions) in 177 patients at risk of HCC without a history of previous treatment for hepatic malignancy in a tertiary center were retrospectively reviewed. Either histopathology results or long-term (> 24 months) follow-up images were used as a standard of reference. All lesions were categorized according to the Liver Imaging Reporting and Data System (LI-RADS), European Association for the Study of the Liver (EASL), Asian Pacific Association for the Study of the Liver (APASL), and Korean Liver Cancer Study Group-National Cancer Center (KLCSG-NCC) guidelines. The sensitivity and specificity thereof were assessed using a generalized estimation equation. RESULTS: For gadoxetic acid-enhanced MRI, LI-RADS (95%, 95% confidence interval [CI] 88-98) and EASL (94%, 95% CI 86-97) yielded the highest specificity, while EASL yielded the lowest sensitivity (54% [95% CI 46-62]). APASL yielded the highest sensitivity (91% [95% CI 86-95]) with the lowest specificity (78% [95% CI 69-86]). KLCSG-NCC showed balanced sensitivity (85% [79-90]) and specificity (88% [95% CI 80-93]). Differences were more prominent in small nodules between 1 and 2 cm. CONCLUSION: The diagnostic performance of current guidelines for HCC on gadoxetic acid-enhanced MRI was significantly different, and a potential inverse association between sensitivity and specificity was observed. KEY POINTS: • EASL and LI-RADS yielded the highest specificity with the lowest sensitivity, whereas APASL yielded the highest sensitivity with the lowest specificity. • Differences in the diagnostic performances of guidelines were prominent in small nodules between 1 and 2 cm. • Additional evaluation of CT findings improved the diagnostic sensitivity and accuracy of EASL and LI-RADS. Although doing so decreased specificity, it remained above 89-90%.