Early Renal Perfusion Scintigraphy Is Associated with Mortality in Experimental Sepsis: A Multimodal Study Integrating Imaging, Survival, and Biomarker Analysis

Background/Objectives:This study aimed to evaluate whether early renal perfusion scintigraphy is associated with sepsis severity and short-term mortality in an experimental polymicrobial sepsis model. Methods: A total of 90 female Wistar albino rats were divided into Control, mild sepsis, and severe sepsis groups using a cecal ligation and puncture (CLP) model. Renal perfusion was evaluated 5 h after sepsis induction using technetium-99m-labeled erythrocyte scintigraphy, expressed as the kidney-to-aorta (R/A) activity ratio. Survival was monitored for 5 days. Histopathological and biochemical analyses were also performed. Results: The kidney-to-aorta (R/A) activity ratio decreased progressively with increasing sepsis severity (all p < 0.001). Kaplan–Meier analysis demonstrated significantly reduced survival in septic animals (log-rank p < 0.001). The R/A ratio showed high discrimination for 5-day mortality (AUC = 0.944, 95% CI 0.902–0.986; p < 0.001). Univariable Cox proportional hazards analysis demonstrated that a lower R/A ratio was significantly associated with an increased hazard of death (HR = 0.005, 95% CI 0.001–0.036; p < 0.001). Histopathological injury scores and biochemical markers (TNF-α, VEGF, STAT3, NGAL, BUN, creatinine, and MDA) increased significantly with sepsis severity. Conclusions: Early Tc-99m-labeled erythrocyte renal perfusion scintigraphy was associated with sepsis severity and short-term mortality in experimental polymicrobial sepsis. These findings support further investigation of this imaging approach as an experimental marker of sepsis severity and outcome; however, external validation is required before clinical translation.