Outpatient Renal Function Screening Before Contrast-Enhanced CT Examinations

Area of Science:

• Nephrology
• Radiology
• Medical Imaging

Background:

• Contrast-induced acute kidney injury (CI-AKI) is a risk with iodinated contrast media, particularly in patients with reduced estimated glomerular filtration rate (eGFR < 30 mL/min/1.73 m²).
• Current guidelines from the American College of Radiology (ACR) and European Society of Urogenital Radiology (ESUR) suggest screening renal function via medical history, but their real-world effectiveness is not well-established.

Purpose of the Study:

• To evaluate the effectiveness of ACR and ESUR guidelines in identifying patients requiring renal function assessment before contrast-enhanced computed tomography (CT).
• To determine the prevalence of low eGFR in an outpatient population undergoing contrast-enhanced CT without prior eGFR measurements.

Main Methods:

• Retrospective analysis of 2,560 adult outpatients undergoing contrast-enhanced CT without recent eGFR data.
• On the day of CT, eGFR was measured. Medical history was assessed against ACR and ESUR screening criteria.
• Prevalence of eGFR < 30 mL/min/1.73 m² and the performance of screening strategies were analyzed.

Main Results:

• 1.1% of patients had an eGFR < 30 mL/min/1.73 m², often associated with a history of gout or renal disease.
• ACR and ESUR strategies identified 16.9% and 38.8% of patients, respectively, capturing 92.6% and 96.3% of those with renal insufficiency.
• Both screening methods showed high negative predictive values, indicating their utility in ruling out significant renal impairment.

Conclusions:

• Selective renal function screening using ACR and ESUR guidelines is effective in identifying patients at risk for CI-AKI before contrast-enhanced examinations.
• These strategies demonstrate high sensitivity and negative predictive values, supporting their use in clinical practice to ensure patient safety.