Comparison of diagnostic criteria for hepatocellular carcinoma < 10 mm on gadoxetic acid-enhanced MRI.

OBJECTIVES: To evaluate and compare the diagnostic performance of typical vascular pattern, the Liver Imaging Reporting and Data System (LI-RADS) category 4 (LR-4 category), the Asian Pacific Association for the Study of the Liver (APASL) and the Korean Liver Cancer Association-National Cancer Center (KLCA-NCC) for diagnosing hepatocellular carcinoma (HCC) < 10 mm using gadoxetic acid-enhanced MRI. METHODS: This retrospective study included 308 patients (mean age, 51.69 ± 11.17 years; 210 men) at high risk for HCC with 352 hepatic lesions < 10 mm on gadoxetic acid-enhanced MRI, including 147 HCC. Diagnostic performance was assessed on a per-lesion basis. Generalized estimating equations with pairwise comparisons were used to compare guidelines. Subgroup analyses were performed according to cirrhosis status. RESULTS: The LR-4 category achieved the highest accuracy (0.756, 95 % CI: 0.708-0.798) among the four diagnostic criteria and also yielded the highest sensitivity (0.816, 95 % CI: 0.746-0.871), although its specificity remained modest (0.712, 95 % CI: 0.647-0.770). Sensitivity did not differ significantly among the APASL, KLCA-NCC, and LR-4 category (all p > 0.05). Compared with APASL, KLCA-NCC showed slightly higher specificity (0.551 vs. 0.654, p = 0.055), whereas LR-4 category demonstrated significantly higher specificity (0.551 vs. 0.712, p < 0.001). The typical vascular pattern provided the highest specificity but the lowest sensitivity. Similar diagnostic performance patterns were also observed in both the cirrhotic and non-cirrhotic subgroups. CONCLUSION: The evaluated diagnostic criteria showed different strengths and limitations in balancing sensitivity and specificity, but their overall diagnostic performance for HCC < 10 mm remained modest, highlighting the need for optimized diagnostic criteria for HCC < 10 mm.