The value of LI-RADS ancillary features and biomarker for hepatocellular carcinoma ≤ 30 mm in Western and Eastern guidelines on extracellular agent and gadoxetic acid-enhanced MRI.

objectivesTo evaluate the diagnostic performance of the Liver Imaging Reporting and Data System (LI-RADS) v2018 ancillary features (AFs) and biomarker for hepatocellular carcinomas (HCCs) ≤ 30 mm in Western and Eastern guidelines. MATERIALS AND

methodsThis multicenter retrospective study included 1414 patients at risk for HCC who underwent MRI. The odds ratios of LI-RADS features and high alpha-fetoprotein (AFP) levels were assessed. Western and Eastern guidelines' diagnostic performances were compared via generalized estimating equations.

resultsA total of 1711 observations ≤ 30 mm were included in the extracellular contrast agent (ECA)-MRI training, internal/external ECA-MRI validation sets (n = 573, 245 and 212), internal EOB-MRI validation set (n = 681). Based on multivariable analysis, using combination of mild-moderate T2 hyperintensity and "either fat in mass or AFP ≥ 200 ng/mL," named "T2 + F/A" criterion, significantly improved the sensitivities of LR-5 v2018 (80.1-85.0% vs. 73.1-77.1%), EASL v2018 (78.4-84.3% vs. 72.2-75.7%), Korean Liver Cancer Association-National Cancer Center (KLCA-NCC) v2022 (78.4-90.9% vs. 73.4-88.3%), Asian Pacific Association for the Study of the Liver (APASL) v2017 (81.5-94.8% vs. 73.7-90.9%) and Japan Society of Hepatology (JSH) v2021 (81.5-94.5% vs. 73.7-90.6%) for HCCs ≤ 30 mm in the training set and internal and external validation sets (all p < 0.05) without impairing specificity, except for that of Asian Pacific Association for the Study of the Liver (APASL) v2017 in the internal gadoxetic acid (EOB) validation set (75.5% vs. 77.2%, p = 0.044).

conclusionTwo LI-RADS AFs (mild-moderate T2 hyperintensity and fat in mass) and AFP ≥ 200 ng/mL are useful for improving the sensitivity of Western and Eastern guidelines for HCCs ≤ 30 mm. KEY POINTS: Question The sensitivities of Western and Eastern guidelines for hepatocellular carcinoma ≤ 30 mm are still insufficient on extracellular contrast agent-enhanced MRI and gadoxetic acid-enhanced MRI. Findings The use of the integrated "T2 + F/A" diagnostic criterion significantly improved the sensitivity of Western and Eastern guidelines for HCCs ≤ 30 mm on both ECA-MRI and EOB-MRI. Clinical relevance Addressing a critical gap in noninvasive small HCC diagnosis protocols in Western and Eastern guidelines across multiple MRI contrast agents. By enabling more accurate MRI diagnosis of HCCs ≤ 30 mm, our findings could increase patients receiving curative treatments at the early stage, potentially improving outcomes.