RESUMO
Objective: To investigate the diagnostic performance of MRI Liver Imaging Reporting and Data System version 2018 in high-risk hepatocellular carcinoma (HCC) patients with intrahepatic parenchymal substantial lesions ≤3.0 cm. Methods: A retrospective analysis was conducted in hospitals between September 2014 to April 2020. 131 pathologically confirmed non-HCC cases with lesions ≤3.0 cm in diameter were randomly matched with 131 cases with lesions ≤3.0 cm in diameter and divided into benign (56 cases), other hepatic malignant tumor (OM, 75 cases), and HCC group (131 cases) in a 1:1 ratio. MRI features of the lesions were analyzed and classified according to LI-RADS v2018 criteria (tie-break rule was applied to lesions with both HCC and LR-M features). Taking the pathological results as the gold standard, the sensitivity and specificity of the LI-RADS v2018 classification criteria and the more stringent LR-5 criteria (with three main signs of HCC at the same time) were calculated for HCC, OM or benign lesions diagnosis. Mann -Whitney U test was used to compare the classification results. Results: The number of cases classified as LR-M, LR-1, LR-2, LR-3, LR-4, and LR-5 in HCC group after applying the tie-break rule were 14, 0, 0, 12, 28, and 77, respectively. There were 40, 0, 0, 4, 17, 14 and 8, 5, 1, 26, 13, 3 cases in benign and OM group, respectively. There were 41 (41/77), 4 (4/14) and 1 (1/3) lesion case in the HCC, OM and benign group, respectively, that met the more stringent LR-5 criteria. The sensitivity of LR-4 combined with LR-5 (LR-4/5) criteria, LR-5 criteria and more stringent LR-5 criteria for HCC diagnosis were 80.2% (105/131), 58.8% (77/131) and 31.3% (41/131), respectively, and the specificity were 64.1% (84/131), 87.0% (114/131) and 96.2% (126/131), respectively. The sensitivity and specificity of LR-M were 53.3% (40/75) and 88.2% (165/187), respectively. The sensitivity and specificity using LR-1 combined with LR-2 (LR-1/2) criteria for the diagnosis of benign liver lesions were 10.7% (6/56) and 100% (206/206), respectively. Conclusions: LR-1/2, LR-5, and LR-M criteria have high diagnostic specificity for intrahepatic lesions with a diameter of ≤3.0 cm. Lesions classified as LR-3 are more likely to be benign. The specificity of LR-4/5 criteria is low, while the more stringent LR-5 criteria has a high specificity for HCC diagnosis.