Dual-Energy Computed Tomography Versus Conventional Magnetic Resonance In-Phase/Opposed-Phase Imaging for Liver Fat Fraction Quantification: A Retrospective Cohort Study

Background/Objectives: Multiple imaging modalities are available for non-invasive hepatic fat quantification. We performed a hypothesis-generating methods-comparison study to compare liver fat fraction (FF) measurements obtained using magnetic resonance imaging (MRI) in-phase/opposed-phase (IP/OP) with dual-energy computed tomography (DECT) multi-material decomposition (MMD) techniques. Methods: This retrospective method-comparison study included 45 patients who underwent abdominal DECT and MRI. Corresponding 2-cm2 regions of interest were placed in hepatic segments VI and VII. DECT and MRI fat fraction measurements were compared using Spearman’s correlation and Bland–Altman and Passing–Bablok analyses. Exploratory receiver operating characteristic area under the curve (ROC AUC) analyses evaluated the ability of DECT fat fraction measurements to discriminate MRI-defined steatosis thresholds. Results: DECT FF was positively associated with MRI FF in segment VI (Spearman’s ρ = 0.50, p < 0.001) and segment VII (ρ = 0.57, p < 0.001). Bland–Altman analysis showed that DECT measurements were lower than MRI measurements on average, with mean biases (MRI—DECT) of 3.39% and 2.57% for segments VI and VII respectively, accompanied by wide limits of agreement. Passing–Bablok analysis showed no statistically significant proportional or constant bias. The ability of DECT FF to classify MRI-defined steatosis improved with increasing disease severity, with AUCs of 0.77 for mild steatosis and 0.88-0.99 for moderate-to-severe steatosis. Conclusions: This preliminary method-comparison study demonstrates an association between DECT and MRI fat fraction measurements and supports the feasibility of DECT for opportunistic hepatic fat quantification. Although exploratory AUC analyses provide preliminary estimates for future validation studies, substantial inter-modality variability currently limits definitive clinical application.