Diagnostic accuracy of prospective application of the Liver Imaging Reporting and Data System (LI-RADS) in gadoxetate-enhanced MRI

Abstract

OBJECTIVES: To evaluate the diagnostic performance of the LI-RADS (v2014) on gadoxetate-enhanced MRI prospectively applied in actual practice. METHODS: We retrospectively reviewed the prospectively written radiology reports of 143 treatment-naive at-risk patients who underwent gadoxetate-enhanced liver MRI from January to December 2014, and identified 202 hepatic observations categorized using the LI-RADS. The diagnostic performances of LI-RADS categories for hepatocellular carcinoma (HCC) and hepatic malignancy were calculated. RESULTS: Twenty (69.0 %) of 29 LR-4, 73 (97.3 %) of 75 LR-5, and all of five (100 %) LR-5V observations were HCCs. The remaining two (2.7 %) LR-5 observations were combined hepatocellular-cholangiocarcinomas, while 10 (76.9 %) of 13 LR-M observations were HCCs. The sensitivity and specificity of LR-5/5V for HCC were 60.5 % and 97.3 %, respectively. Including LR-M in the diagnostic criteria for HCC increased sensitivity (68.2 %, p = 0.002) but decreased specificity without statistical significance (93.2 %, p = 0.154). LR-5/5V/M yielded sensitivity of 68.9 % and specificity of 100.0 % for hepatic malignancy. CONCLUSIONS: LI-RADS v2014 was successfully applied on gadoxetate-enhanced MRI in clinical practice. LR-5/5V was the most specific diagnostic measure for HCC, but most LR-M observations were HCCs and a considerable portion of non-HCC malignancies were categorized as LR-4 or LR-5. KEY POINTS: * LR-5/5V provided a highly specific diagnosis for HCC. * Half of non-HCC malignancies were categorized as LR-4 or LR-5. * The majority of LR-M observations were finally diagnosed as HCCs. * More sensitive diagnosis of HCC was feasible with LR-5/5V/M on gadoxetate-enhanced MRI. * Observations in either LR-5/5V or LR-M categories were definitely malignant.