Quantification of liver steatosis using rapid kilovoltage-switching dual-energy computed tomography in individuals who are overweight or obese.

OBJECTIVES

To validate the capability of dual-energy computed tomography (DECT) to quantify liver fat in individuals who are overweight or obese and assess the sex-based differences.

METHODS

This retrospective, single-center study involved individuals who were pre-screened or enrolled in a time-restricted eating study between April 2019 and August 2021 and underwent both DECT and MRI. Participants were stratified into four groups according to the hepatic fat content quantified using the MRI-proton density fat fraction (MRI-PDFF). Receiver operating characteristic curves for the ability of DECT-fat volume fraction (DECT-FVF) or CT values at 74-keV to grade hepatic steatosis were plotted and optimal thresholds determined.

RESULTS

A total of 130 participants who were overweight or obese (median age: 31.2 years [interquartile range, 12.5 years]; men, n = 69) were enrolled in the study. Both DECT-FVF and CT values at 74-keV were highly correlated with MRI-PDFF (Spearman's r = 0.933 [0.963 for males, 0.843 for females] and - 0.954 [-0.977 for males, -0.895 for females], respectively). The optimal cutoff DECT-FVF/CT values at 74-keV for identifying participants with mild or greater steatosis were 5.3 %/55.9 HU for all participants, 3.8 %/56.5 HU for males, and 2.1 %/56.3 HU for females, with corresponding areas under the curve values of 0.92/0.94, 0.95/0.98, and 0.86/0.89.

CONCLUSIONS

DECT-FVF and CT values at 74-keV image can effectively quantify hepatic steatosis in individuals who are overweight or obese. Sex-specific diagnostic thresholds for DECT should be considered to achieve accurate stratification of dichotomized hepatic steatosis grading.