Diagnostic performance of ultrasound-derived fat fraction for assessing steatotic liver disease with histopathology as the reference

PURPOSE: This study was performed to evaluate the diagnostic performance of ultrasound-derived fat fraction (UDFF) for detecting hepatic steatosis in patients with steatotic liver disease (SLD), using liver biopsy and histopathology as the gold standard. METHODS: In this prospective study, patients referred for evaluation of suspected SLD were enrolled. All patients underwent UDFF and controlled attenuation parameter (CAP) measurements. Histopathological findings were assessed using the steatosis-activity-fibrosis scoring system as the gold standard. Pearson or Spearman correlation analyses and multivariate linear regression were performed. Areas under the receiver operating characteristic curves (AUCs) were utilized to assess the diagnostic performance of UDFF and CAP in identifying hepatic steatosis. The DeLong test was used to compare AUCs. RESULTS: From February 2023 to May 2025, 66 patients were included. The median body mass index was 24 kg/m2. UDFF was positively correlated with hepatic steatosis grade (r=0.66). Using UDFF thresholds of 9.5%, 14.5%, and 16.3% (determined by the Youden index), the AUCs for detecting steatosis grades ≥S1, ≥S2, and S3 were 0.82, 0.90, and 0.99, respectively. UDFF exhibited a significantly higher AUC than CAP for detecting steatosis grade S3 (P=0.037). UDFF was correlated with hepatic steatosis grade, activity grade, CAP, aspartate aminotransferase level, and albumin level (all P<0.05). CONCLUSION: UDFF demonstrated good diagnostic performance for assessing hepatic steatosis, using histopathology as the reference. UDFF may serve as a quantitative imaging approach to measure liver fat content in patients with SLD.