A modified Rim APHE criterion to improve LI-RADS diagnostic performance for primary liver malignancies

To refine the diagnostic criteria for rim arterial phase hyperenhancement (Rim APHE) and to evaluate the impact of this modification on the diagnostic performance for primary liver malignancies.

This multicenter, retrospective study included patients with pathologically confirmed primary liver malignancies who underwent preoperative magnetic resonance imaging (MRI) before June 2021. Thirteen different measurement methods for Rim APHE were evaluated to determine the optimal criterion based on diagnostic performance. Two radiologists independently reviewed all observations, assigned Liver Imaging Reporting and Data System (LI-RADS) categories according to version 2018. The diagnostic performance of LI-RADS using original versus modified Rim APHE criteria was compared.

The study enrolled 272 patients, including 204 with Hepatocellular carcinoma (HCC) (170 men and 34 women; mean age, 57 years ±10) and 68 with non-HCC malignancies (53 men and 15 women; mean age, 56 years ±10). The optimal criterion for Rim APHE was the total thickness of the thickest part of peripheral hyperenhancement to tumor diameter (area under the receiver operating characteristic (ROC) curve [AUC] = 0.852; P < .001). With implementation of the modified Rim APHE criterion, the LR-5 criteria showed significantly superior AUC (0.770 vs. 0.752, p = .007), sensitivity (76.0% vs. 72.5%, p = .016) and accuracy (76.5% vs. 73.9%, p = .016); the LR-M criteria showed higher AUC (0.831 vs. 0.811, p = .004), specificity (92.7% vs. 88.7%, p = .008) and accuracy (87.9% vs. 84.9%, p = .008).

The optimal criterion for Rim APHE can improve the diagnostic performance for both HCC and non-HCC malignancies.