Utility of Attenuation Coefficient Measurement Using an Ultrasound-Guided Attenuation Parameter for Evaluation of Hepatic Steatosis: Comparison With MRI-Determined Proton Density Fat Fraction.

Abstract

Recently, a new method was developed to diagnose hepatic steatosis by measuring attenuation coefficients that are based on the ultrasound-guided attenuation parameter (UGAP). We investigated the diagnostic ability of these coefficients to detect steatosis that was identified using the proton density fat fraction (PDFF) on MRI in patients with chronic liver disease. A total of 126 patients with chronic liver disease (non-hepatitis B, non-hepatitis C) were analyzed. The diagnostic ability of UGAP-determined attenuation coefficients was evaluated using ROC curve analysis, and the correlation between MRI-determined PDFF values and attenuation coefficient values was determined. The correlation coefficient (r) between PDFF values and attenuation coefficient values was 0.746 (95% CI, 0.657-0.815) (p < 0.001), corresponding to a strong relationship. The diagnostic ability of attenuation coefficients for steatosis grades ≥ 1, ≥ 2, and 3 as determined by PDFF were 0.922 (95% CI, 0.870-0.973), 0.874 (95% CI, 0.814-0.934), and 0.892 (95% CI, 0.835-0.949), respectively. The r between PDFF values and attenuation coefficient values was 0.559 (95% CI, 0.391-0.705) (p < 0.001) in patients with mild or no steatosis (grade ≤ 1). In addition, the r between PDFF values and attenuation coefficient values was 0.773 (95% CI, 0.657-0.853) (p < 0.001) in obese patients (body mass index [weight in kilograms divided by the square of height in meters] ≥ 25). The diagnostic ability of attenuation coefficients for patients with steatosis grades ≥ 1, ≥ 2, and 3 as determined by PDFF were 0.884 (95% CI, 0.792-0.976), 0.863 (95% CI, 0.778-0.947), and 0.889 (95% CI, 0.813-0.965), respectively. UGAP-determined attenuation coefficient values had a good diagnostic ability to detect hepatic steatosis.