Iodine-based spectral CT can quantify transient kidney injury in hemorrhagic shock: Results from a translational large-animal model.

Abstract

After severe hemorrhage and polytrauma, late complications such as multi-organ failure (MOF) remain major contributors to morbidity and mortality. Especially after hemorrhagic shock the kidney is known to be at high risk. As laboratory parameters, like creatinine, provide only delayed and indirect information about kidney function, our study evaluated whether iodine-based spectral computed tomography (SDCT) can quantify renal perfusion in a large-animal polytrauma model. Thirty-two Landrace pigs (70±5 kg) were used, randomized into four groups (n=8). Tissue trauma group (TTFx) received a blunt chest injury and bilateral femur shaft fractures. In the shock (HS) group, hemorrhagic shock was induced by controlled blood withdrawal. The polytrauma (PT) group underwent tissue trauma and hemorrhagic shock. Eight uninjured pigs served as controls. Whole-body SDCT with iodine mapping was performed after trauma and after 24 hours. Serum creatinine was measured in parallel. Urine was sampled at baseline, after resuscitation, and after 24 hours. Significant differences in renal perfusion measured by iodine uptake were found during shock and after polytrauma: groups with hemorrhagic shock showed reduced renal perfusion compared with controls (P<0.001). Decreased iodine uptake correlated strongly with increased creatinine levels (ρ=-0.505, P=0.009). Hemorrhagic shock caused pronounced intrarenal functional impairment, reflected by elevated fractional sodium excretion (FENa 2.49% vs. 0.35%, P<0.001), reduced urine osmolality (P<0.001), and decreased urinary urea concentrations (P<0.001). Fractional calcium excretion (FECa), a novel parameter, was strongly increased in the shock group (6.18% vs. 0.19%, P<0.001). After 24-hour resuscitation, no significant differences between the groups were observed in either iodine uptake, creatinine levels, or urinary parameters. Spectral iodine imaging seems to reflect renal perfusion impairment after hemorrhagic shock. The observed correlations with creatinine and urinary parameters suggest that spectral CT may provide a rapid, imaging-based assessment of kidney dysfunction. The renal perfusion normalizes with resuscitation along with renal function parameters. (J Trauma Acute Care Surg. 2026;101: 121-128. c 2026 The Author (s). Published by Wolters Kluwer Health, Inc. on behalf of the American Association for the Surgery of Trauma.). Not applicable.