Diagnostic performance of ultrasound-measured visceral fat thickness and metabolic indices for MRI-PDFF-defined hepatic steatosis in MAFLD

Metabolic dysfunction-associated fatty liver disease(MAFLD) has emerged as a globally significant liver disorder due to its continuously rising prevalence. Our aim is to investigate the clinical value of ultrasound-measured visceral fat thickness (VFT) and five scoring systems—fatty liver index (FLI), hepatic steatosis index (HSI), lipid accumulation product (LAP), visceral adiposity index (VAI), and homeostatic model assessment of insulin resistance (HOMA‑IR)—in evaluating MRI-PDFF-defined hepatic steatosis in MAFLD. This single-center prospective study enrolled 142 patients with MAFLD and 57 non-MAFLD control subjects. VFT was measured via ultrasound, and FLI, HSI, LAP, VAI, and HOMA‑IR scores were calculated. Using magnetic resonance imaging proton density fat fraction (MRI-PDFF) as the reference standard for hepatic steatosis quantification in MAFLD, receiver operating characteristic (ROC) curve analyses were performed to assess the ability of VFT and the five scoring systems to diagnose different grades of hepatic steatosis in MAFLD. The area under the curve (AUC) for diagnosing mild steatosis in MAFLD (S ≥ S1) using VFT, FLI, HSI, LAP, VAI, and HOMA‑IR were 0.841 (95% CI 0.781–0.902), 0.849 (95% CI 0.793–0.904), 0.809 (95% CI 0.747–0.871), 0.801 (95% CI 0.736–0.865), 0.739 (95% CI 0.663–0.815), and 0.774 (95% CI 0.705–0.843). For diagnosing moderate‑to‑severe steatosis in MAFLD (S ≥ S2), the corresponding AUC values were 0.828 (95% CI 0.770–0.885), 0.853 (95% CI 0.800–0.906), 0.877 (95% CI 0.829–0.925), 0.785 (95% CI 0.720–0.849), 0.734 (95% CI 0.664–0.804), and 0.822 (95% CI 0.764–0.879). VFT and five scoring systems, especially FLI and HSI, demonstrated favorable diagnostic performance in assessing different hepatic steatosis grades in MAFLD.