Diagnostic Thresholds and Clinical Value of Ultrasound-Derived Fat Fraction in Assessing Hepatic Steatosis: Insights from a Prospective Study

Background A reliable assessment of hepatic steatosis is imperative for the effective management of metabolic dysfunction-associated steatotic liver disease (MASLD). This study assesses the effectiveness of ultrasound-derived fat fraction (UDFF) in measuring hepatic steatosis and determines diagnostic thresholds for different severity levels. Methods This prospective cross-sectional study involved 79 participants (mean age 42.8 ± 13.8 years) recruited from two centers. MRI proton density fat fraction (PDFF) served as the reference standard for assessing hepatic steatosis. Pearson correlation coefficients were applied to determine the relationship between UDFF and MRI-PDFF, while Bland-Altman analysis evaluated the measurement consistency between UDFF and PDFF.ROC curve analysis evaluated the diagnostic performance of UDFF against visual score, Fatty Liver Index (FLI), the CAP score (CAPS), and Hepatic Steatosis Index (HSI). Results The UDFF showed a strong correlation with MRI-PDFF (r = 0.84, p < 0.001), with a mean bias of 2.06% and 95% limits of agreement ranging from − 7.03–11.15%. The AUC values for UDFF in diagnosing steatosis grades ≥ S1, ≥S2, and S3 were 0.95, 0.97, and 0.94, respectively, outperforming visual score, FLI, CAPS, and HSI. The optimal UDFF cutoff values for these grades were 8.5%, 16.5%, and 22%. Conclusion UDFF shows high consistency in diagnostic performance with PDFF and steatosis grades, although UDFF values tend to be slightly higher than those of PDFF.