Risk of Contrast-Induced Acute Kidney Injury in Computed Tomography: A 16 Institutional Retrospective Cohort Study.

Objectives: Concern about contrast-induced acute kidney injury (CI-AKI) may delay the timely administration of contrast media for computed tomography (CT). The precise causative effect of iodinated contrast media on CI-AKI and its relevant risk factors remains an area of ongoing investigation. Therefore, this study aimed to determine the risk of CI-AKI following contrast-enhanced CT and its predisposing risk factors.

Materials and methods: This study employed a 1:1 propensity score matching analysis using electronic medical records gathered between January 2006 and December 2022 from 16 institutions in South Korea. Contrast-enhanced and nonenhanced CT scans in patients aged 18 years and above were matched for baseline estimated glomerular filtration rate (eGFR), demographic characteristics, and clinical variables to assess the risk of CI-AKI. Subgroup analyses were conducted to evaluate any significant risk factors for CI-AKI.

Results: A total of 182,170 CT scans with contrast were matched to 182,170 CT scans without contrast. The risk of CI-AKI in the entire study cohort was not statistically significant (odds ratio [OR], 1.036; 95% confidence interval [CI], 0.968-1.109; P = 0.34). Subgroup analyses revealed a significantly higher risk of CI-AKI in patients with eGFR <30 mL/min/1.73m 2 (OR, 1.176; 95% CI, 1.080-1.281; P = 0.011) or eGFR 30-45 mL/min/1.73m 2 (OR, 1.139; 95% CI, 1.043-1.244; P = 0.019), patients diagnosed with chronic kidney disease (OR, 1.215; 95% CI, 1.084-1.361; P = 0.011), and those administered with iso-osmolar contrast media (OR, 1.392; 95% CI, 1.196-1.622; P = 0.011).

Conclusions: The risk of CI-AKI following CT was minimal in the general population. However, caution is warranted for patients with chronic kidney disease and eGFR lower than 45 mL/min/1.73m 2 , or those administered with iso-osmolar contrast media.