Diagnostic Performance of Ultrasound-Based Liver Fat Quantification With Reference to Magnetic Resonance Imaging Proton Density Fat Fraction and Histology.

Objective: To investigate the diagnostic performance of ultrasound attenuation imaging technology (USAT) in the evaluation of hepatic steatosis using magnetic resonance imaging proton density fat fraction (MRI PDFF) and histology as reference standards.

Methods: In this single-center, prospective study, the liver fat content of 117 potential liver donor candidates was assessed by USAT and MRI PDFF between April and August 2024. Intraoperative liver biopsy was performed in 47 liver donors. Cut-off values of 6%, 17%, 22%, and 5%, 33%, 66% were used for mild, moderate, and severe steatosis in MRI PDFF and histology, respectively. The correlation between USAT and MRI PDFF was evaluated using Spearman's rho technique. Receiver operating characteristic (ROC) analysis was performed for the diagnostic performance of USAT, and optimal USAT cut-off values for different grades of hepatosteatosis were obtained.

Results: There was a very strong correlation between USAT and MRI PDFF (rho = 0.933, p < 0.001). For MRI PDFF values greater than 6%, the area under the curve (AUC) was 0.97 [95% confidence interval (CI): 0.93-0.99] (p < 0.001). USAT cut-off values for differentiating between different grades of liver steatosis were 0.57, 0.68, and 0.76 dB/cm/MHz for mild, moderate, and severe steatosis, with sensitivities of 88.9%, 90.0%, and 86.7%, respectively. For histologically confirmed steatosis greater than 5%, the AUC was 0.94 (95% CI: 0.83-0.99) (p < 0.001), with a cut-off of 0.56 dB/cm/MHz for 84.6% sensitivity.

Conclusions: USAT demonstrates excellent diagnostic accuracy in both the quantification and grading of hepatic steatosis.