Abstract
Background: Contrast-associated acute kidney injury (CA-AKI) is a clinically important complication following contrast-enhanced computed tomography (CT), particularly in emergency department (ED) populations. While several risk scores have been proposed, their comparative performance in ED-based imaging remains uncertain. Methods: This retrospective single-center study included 472 adult patients who underwent contrast-enhanced CT between November 2023 and November 2024. Patients with end-stage kidney disease, renal transplantation, baseline eGFR < 30 mL/min/1.73 m(2), or incomplete laboratory data were excluded. CA-AKI was defined as an increase in serum creatinine ≥ 0.3 mg/dL or ≥25% within 48-72 h after contrast exposure in the absence of alternative causes. The Mehran score, Pre-CT AKI score, and immunonutritional indices-including the Prognostic Nutritional Index (PNI), Osaka Prognostic Score (OPS), and Glasgow Prognostic Score (GPS)-were calculated. Predictive performance was evaluated using logistic regression and receiver operating characteristic (ROC) curve analyses. Results: The incidence of CA-AKI was 2.1% (n = 10). Patients who developed CA-AKI were older and had more comorbidities, particularly chronic kidney disease, diabetes, and cardiovascular disease. In univariate analysis, baseline eGFR, Pre-CT AKI score, and PNI were significantly associated with CA-AKI. Multivariate logistic regression identified baseline eGFR and PNI as independent predictors. The Pre-CT AKI score demonstrated the highest discriminative ability (AUC = 0.87), outperforming the Mehran score (AUC = 0.74). PNI provided complementary prognostic value (AUC = 0.71), whereas OPS and GPS did not reach statistical significance. Conclusions: In ED patients undergoing contrast-enhanced CT, the Pre-CT AKI score was the most accurate predictor of CA-AKI, while PNI offered additional prognostic information reflecting immunonutritional vulnerability. The Mehran score showed moderate usefulness, whereas OPS and GPS were less applicable. Incorporating multifactorial models that integrate clinical, hemodynamic, and immunonutritional factors may improve early risk stratification and guide preventive strategies for CA-AKI in emergency settings.