Discovering of ultrasound-derived fat fraction as a non-invasive and efficient identification for nonalcoholic fatty liver disease

Background This study aimed to investigate ultrasound-derived fat fraction (UDFF) as a diagnostic alternative to magnetic resonance imaging proton density fat fraction (MRI-PDFF), the noninvasive diagnostic gold standard, in metabolic dysfunction-associated steatotic liver disease (MASLD), together with comparing the diagnostic ability of UDFF with controlled attenuation parameter (CAP). Methods The diagnostic criteria for MASLD were used, we included 103 individuals with 53 MASLD patients and 49 healthy controls. All participants underwent liver MRI to measure MRI-PDFF and liver ultrasonography to measure UDFF and CAP. The receiver operating characteristic (ROC) curves were to determine the efficacy of UDFF and CAP in diagnosing MASLD. Finally, we analyzed the correlation between UDFF and serological indicators and the consistency between UDFF and MRI-PDFF. Results The median of the UDFF mean was 6%. In addition, the median CAP and median MRI-PDFF values were 246dB/m and 5.44%, respectively. Overall, UDFF was positively linked with MRI-PDFF (R = 0.876; P  < 0.001), and CAP was positively linked with MRI-PDFF (R = 0.792, P  < 0.001). For diagnosing 5% and above MRI-PDFF, UDFF was noted to have a mean AUC of 0.981. Additionally, CAP was noted to have an AUC of 0.932 in diagnosing MASLD. In addition, the Bland-Altman difference plots showed overall UDFF and MRI-PDFF, with a mean deviation of -0.2%. A linear regression model between the difference and the mean suggested proportional error. Conclusions Ultrasound testing for UDFF provides a simple and noninvasive clinical tool to quantify the extent of hepatic steatosis. The diagnostic efficacy of UDFF is superior to CAP, which could be a noninvasive alternative to MRI-PDFF.