Diagnostic value of dual-energy CT in detecting irreversible transmural intestinal necrosis in patients with acute occlusive mesenteric ischemia

Background Irreversible transmural intestinal necrosis (ITIN) is associated with high mortality rates in patients with acute occlusive mesenteric ischemia (AOMI). However, the important radiographic predictors of ITIN remain unknown. This study evaluated the diagnostic value of dual-energy CT (DECT) for ITIN in AOMI. Methods The cases and CT images of 102 patients with clinically diagnosed AOMI (including 48 ITIN) from January 2012 to January 2022 were retrospectively collected. The CT scans included both MDCT and DECT. Two radiologists independently completed the subjective visual assessment of CT signs related to AOMI. DECT scans the portal vein phase raw data to reconstruct a 120 kVp mixed energy image, 50 keV virtual monoenergetic imaging (VMI), and iodine map. Objective parameters, including CT values (CT 50 keV lesion, CT 50 keV normal/lesion) and iodine concentrations (IC lesion and IC normal/lesion), were quantified. Furthermore, multivariate logistic regression, receiver operating characteristic (ROC) curves, and area under the curve (AUC) values were used to evaluate the subjective/objective indicators in predicting ITIN. Results Regarding subjective signs, logistic regression analysis revealed reduced or absent bowel wall enhancement (odds ratio [OR] = 5.576, 95% confidence interval [CI]: 1.547–20.093), bowel dilation (OR = 11.613, 95% CI: 3.790–35.586), and parenchymatous organ infarction (OR = 4.727, 95% CI: 1.536–14.551) were independent risk factors for the ITIN. CT subjective signs had a high diagnostic efficacy for ITIN (AUC = 0.853). The two DECT objective parameters also exhibited excellent diagnostic value for ITIN, with an AUC of 0.79, a CT cutoff value of CT _{50keV normal/lesion} = 2.81, and an AUC of 0.777 with a cut-off value of IC _{normal/lesion} = 2.39. Importantly, the Delong test showed that there was no significant difference in the efficacy of subjective CT signs and objective DECT parameters (p > 0.05), indicating that the two objective parameters could replace CT signs in predicting ITIN. Furthermore, we observed that IC _{normal/lesion} combined with subjective signs (bowel dilation and parenchymatous organ infarction) had the highest predictive performance (AUC = 0.896), sensitivity (100%), and specificity (70.83%). Conclusion IC _{normal/lesion} (DECT-based features) combined with CT signs showed favorable predictive performance for ITIN in AOMI, which may help clinicians develop timely treatment strategies.