A New Reporting System for Diagnosis of Hepatocellular Carcinoma in Chronic Hepatitis B With Clinical and Gadoxetic Acid-Enhanced MRI Features.

Background Current major guidelines for diagnosis of hepatocellular carcinoma (HCC) based on imaging findings are different from each other and do not include clinical risk factors as a diagnostic criteria. Purpose To developed and validated a new diagnostic score system using MRI and clinical features as applied in chronic hepatitis B patients. Study type Retrospective observational study. Subject A total of 418 treatment-naive patients (out of 902 patients) with chronic hepatitis B having 556 lesions suspected for HCC which were eligible for curative treatment. Field strength/sequence T1W GRE in- and opposed-phase, T2W FSE, DWI, and T1W 3D-GRE dynamic contrast-enhanced sequences at 1.5 T and 3 T. Assessment Six radiologists with 7-22 years of experience independently evaluated MR images based on Liver Imaging Reporting and Data System (LI-RADS) version 2018. Statistical tests Based on logistic regression analysis of MRI features and clinical factors, a risk score system was devised in derivation cohorts (268 patients, 352 lesions) and externally validated (150 patients, 204 lesions). The performance of the new score system was assessed by Harell's c-index. Using cutoff value of 12, maintaining positive predictive value ≥95%, the diagnostic performances of the score system were compared with those of LR-5. Results The 15-point diagnostic scoring system used MRI features (lesion size, nonrim arterial phase hyperenhancement, portal venous phase hypointensity, hepatobiliary phase hypointensity, and diffusion restriction) and clinical factors (alpha-fetoprotein and platelet). It showed good discrimination in the derivation (c-index, 0.946) and validation cohorts (c-index, 0.907). Using a risk score of 12 as a cut-off, this system yielded higher sensitivity than LR-5 (derivation cohort, 76.8% vs. 52.1%; validation cohort, 73.4% vs. 49.5%) without significant decrease in specificity (derivation cohort, 93.1% vs. 97.2%, P = 0.074; validation cohort, 91.7% vs. 96.1%, P = 0.299). Data conclusion A new score system showed improved sensitivity in chronic hepatitis B patients compared to LI-RADS without significant compromise in specificity. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.