Ultrasonic radio frequency signals-based hepatorenal index improved the diagnostic performance in steatotic liver...

To evaluate the feasibility and diagnostic performance of HepatoRenal index plus (HRI⁺) measurements based on ultrasonic radio frequency (RF) signals, compared to auto-hepatorenal index (HRI) measurements based on B-mode ultrasound (BMUS) images.

In this prospective study, patients referred for evaluation of suspected steatotic liver disease by abdominal ultrasound or liver biopsy were enrolled. All patients underwent HRI⁺ and auto-HRI measurements using a Resona A20 ultrasound system (Mindray, China). Pearson or Spearman correlation coefficient was performed based on the normality of distribution. Bland-Altman analysis and area under the curve (AUC) were performed.

From November 2023 to December 2024, 303 patients were included. The median age was 43 years (interquartile range [IQR]: 34-61), and 51.8% (157/303) of the patients were female. The median body mass index was 25.8 kg/m² (IQR: 22.8-29.0). HRI⁺ values had a very low correlation with skin-to-liver capsule distance (r = 0.13) and did not correlate with the depth of regions of interest (ROIs). Auto-HRI values correlated with skin-to-liver capsule distance (r = 0.43) and depth of ROIs (r = 0.20). HRI⁺ and auto-HRI values had a mean bias of -0.17 and a correlation coefficient of 0.61. In a subgroup of 43 patients with histological results, HRI⁺ measurements showed higher diagnostic performance in detecting moderate and severe hepatic steatosis (AUCs = 0.77-0.91) compared to auto-HRI measurements (AUCs = 0.44-0.69). The cutoff values of HRI⁺ for diagnosing hepatic steatosis grades ≥ S1, ≥ S2, and S3 were 1.03, 1.11, and 1.22, respectively.

HRI⁺ measurements were not affected by measurement depth and image post-processing. Compared to auto-HRI measurements, HRI⁺ measurements demonstrate higher feasibility and diagnostic performance in assessing hepatic steatosis.