SHOULD CONTRAST-ENHANCED COMPUTED TOMOGRAPHY BE WITHHELD IN PATIENTS WITH IMPAIRED KIDNEY FUNCTION? A NARRATIVE REVIEW OF CURRENT EVIDENCE

Intravenous iodinated contrast media improve the diagnostic performance of contrast-enhanced computed tomography (CECT), but concerns about acute kidney injury continue to influence its use in patients with impaired kidney function. This narrative review evaluates current evidence on the kidney safety of modern intravenous iodinated contrast media and examines whether clinically indicated CECT should be withheld in these patients. PubMed and professional guidelines were searched for controlled observational studies, propensity-adjusted analyses, systematic reviews, randomized prophylaxis trials and consensus recommendations concerning intravenous iodinated contrast administration. Evidence distinguishes contrast-associated acute kidney injury, which indicates a temporal relationship, from contrast-induced acute kidney injury, which implies causation. The additional risk attributable to modern intravenous iodinated contrast media appears minimal in patients with a stable estimated glomerular filtration rate (eGFR) ≥45 mL/min/1.73 m². Risk also remains low in most patients with eGFR 30–44 mL/min/1.73 m², although diabetes and concurrent kidney insults may increase susceptibility. Greater uncertainty persists in patients with eGFR <30 mL/min/1.73 m² or active acute kidney injury. These conditions should prompt individualized risk–benefit assessment rather than automatic exclusion from CECT. Routine prophylactic hydration is generally unnecessary when eGFR is stable at ≥30 mL/min/1.73 m² but may be considered in selected high-risk patients. When contrast enhancement is necessary to answer a clinical question, the potential kidney risk should be balanced against the consequences of delayed, missed or incomplete diagnosis. Impaired kidney function alone should therefore not determine whether clinically necessary CECT is performed.