Diagnostic performance of Liver Imaging Reporting and Data System in patients at risk of both hepatocellular carcinoma and metastasis

Objective The purpose of this study was to evaluate the diagnostic performance of the Liver Imaging Reporting and Data System (LI-RADS) in patients with both chronic liver disease and a history of extrahepatic malignancy. Materials and methods This retrospective study included 59 hepatocellular carcinomas (HCCs) and 45 metastases pathologically confirmed between 2008 and 2017 in 104 patients with chronic liver disease (cirrhosis or chronic hepatitis B) and a history of extrahepatic malignancy. Two radiologists blinded to the final diagnosis independently reviewed MRI (95 patients) or CT (9 patients) images, and their consensus data were used to calculate the diagnostic performance of LI-RADS categories. Serum tumor markers, tumor multiplicity, and suspected metastatic lymph nodes were also evaluated. Results The sensitivity, specificity, and accuracy of LR-5 for diagnosing HCC were 69% (95% confidence intervals [CI] 56-81), 98% (95% CI 88-99), and 82% (95% CI 73-89), respectively, and those of LR-M for diagnosing metastasis were 89% (95% CI 76-96), 88% (95% CI 77-95), and 88% (95% CI 81-94), respectively. Elevation of serum carcinoembryonic antigen (P = 0.01) or carbohydrate antigen 19-9 levels (P = 0.02) and tumor multiplicity (P = 0.004) were more frequently observed in metastasis than in HCC. Three of four metastases categorized as LR-4 or LR-5 were smaller than 2 cm. Conclusions The LI-RADS provides high specificity (98%) for differentiating HCC from metastases in patients with both chronic liver disease and a history of extrahepatic malignancy.