BackgroundThe Liver Imaging Reporting and Data System (LI‐RADS) is widely used for diagnosing hepatocellular carcinoma (HCC), however, with unsatisfactory sensitivity, complex ancillary features, and inadequate integration with gadoxetate disodium (EOB)‐enhanced MRI.PurposeTo modify LI‐RADS (mLI‐RADS) on EOB‐MRI.Study TypeSecondary analysis of a prospective observational study.PopulationBetween July 2015 and September 2018, 224 consecutive high‐risk patients (median age, 51 years; range, 26–83; 180 men; training/testing sets: 169/55 patients) with 742 (median size, 13 mm; interquartile range, 7–27; 498 HCCs) LR‐3/4/5 observations.Field Strength/Sequence3.0 T T2‐weighted fast spin‐echo, diffusion‐weighted spin‐echo based echo‐planar, and 3D T1‐weighted gradient echo sequences.AssessmentThree radiologists (with 5, 5, and 10 years of experience in liver MR imaging, respectively) blinded to the reference standard (histopathology or imaging follow‐up) reviewed all MR images independently. In the training set, the optimal LI‐RADS version 2018 (v2018) features selected by Random Forest analysis were used to develop mLI‐RADS via decision tree analysis.Statistical TestsIn an independent testing set, diagnostic performances of mLI‐RADS, LI‐RADS v2018, and the Korean Liver Cancer Association (KLCA) guidelines were computed using a generalized estimating equation model and compared with McNemar's test. A two‐tailed P < 0.05 was statistically significant.ResultsFive features (nonperipheral “washout,” restricted diffusion, nonrim arterial phase hyperenhancement [APHE], mild–moderate T2 hyperintensity, and transitional phase hypointensity) constituted mLI‐RADS, and mLR‐5 was nonperipheral washout coupled with either nonrim APHE or restricted diffusion. In the testing set, mLI‐RADS was significantly more sensitive (72%) and accurate (80%) than LI‐RADS v2018 (sensitivity, 61%; accuracy 74%; both P < 0.001) and the KLCA guidelines (sensitivity, 64%; accuracy 74%; both P < 0.001), without sacrificing positive predictive value (mLI‐RADS, 94%; LI‐RADS v2018, 94%; KLCA guidelines, 92%).Data ConclusionIn high‐risk patients, the EOB‐MRI‐based mLI‐RADS was simpler and more sensitive for HCC than LI‐RADS v2018 while maintaining high positive predictive value.Level of Evidence2Technical EfficacyStage 2