Contrast Media-Associated Nephrotoxicity: A Narrative Review of Pathophysiology, Risk Factors, Prevention, and Clinical Management

Background: Contrast media are essential tools in diagnostic and interventional imaging, but their relationship with acute kidney injury remains clinically relevant and conceptu-ally debated. This narrative review aimed to synthesize current evidence on contrast me-dia-associated nephrotoxicity, including terminology, epidemiology, pathophysiology, risk stratification, prevention, pharmacotherapeutic management, and clinical deci-sion-making. Methods: A structured literature search was conducted in major biomedical databases and complemented by international guidelines and consensus statements ad-dressing contrast-associated and contrast-induced acute kidney injury in adults exposed to intravascular contrast media. Discussion: Contemporary evidence emphasizes the dis-tinction between contrast-associated acute kidney injury, which reflects a temporal asso-ciation after exposure, and contrast-induced acute kidney injury, which implies causality. The renal risk directly attributable to modern intravenous iodinated contrast media ap-pears to have been historically overestimated, although clinically relevant risk persists in vulnerable patients. Proposed mechanisms include renal vasoconstriction, medullary hy-poxia, oxidative stress, mitochondrial dysfunction, tubular epithelial injury, endothelial dysfunction, and inflammatory or apoptotic pathways. Preventive strategies should be in-dividualized, with isotonic saline remaining the main intervention when indicated, whereas routine pharmacologic prophylaxis is not supported by consistent clinically meaningful benefit. Conclusions: Renal safety in contrast-enhanced imaging requires a balanced approach that minimizes avoidable kidney injury in high-risk patients without unnecessarily delaying clinically indicated diagnostic or therapeutic procedures.