Quantification of liver fat content with ultrasonographic attenuation measurement function: Correlation with unenhanced multidimensional computerized tomography

Abstract

PurposeTo evaluate the efficacy of attenuation measurement function (ATT), a newly developed quantitative ultrasonography(US) method based on measurement of the attenuation coefficient, using unenhanced computerized tomography(CT) attenuation values as a reference standard, for the detection and measurement of hepatosteatosis. Material and methodsA total of 98 patients were analyzed. The diagnostic ability of ATT was evaluated using receiver operating characteristic (ROC) curve analysis, and the correlation between liver attenuation index (LAI), the liver-to-spleen attenuation ratio (CTL/S), liver attenuation value (CTL), and ATT was determined. ResultsATT is negatively correlated with LAI (r = −0.571, p < 0.001), CTL/S (r = −0.532, p < 0.001), and mean CTL (r = −0.50, p < 0.001). A significant difference was found between ATT values of patients with different grades of hepatosteatosis (p < 0.001). A significant difference was found between ATT values of patients with LAI < −10 and LAI > −10, CTL < 40 and CTL > 40, and CTL/S < 1 and CTL/S > 1 (p < 0.001). An ATT ≥ 0.665 showed a sensitivity of 100% and a specificity of 90% in diagnosing moderate-severe steatosis. The corresponding area under the ROC curve(AUROC) was 0.935. The intraclass correlation coefficient for the interobserver variability of ATT was 0.907 (95% CI, 0.85–0.95). ConclusionIn conclusion, ATT values for evaluation of hepatosteatosis was closely correlated with the degree of hepatosteatosis and liver fat content. It can be used as a noninvasive method in the diagnosis and follow-up.