A patient with an estimated GFR of 28 mL/min/1.73m² requires contrast-enhanced CT. The MOST appropriate iodinated contrast agent strategy to reduce the risk of contrast-induced nephropathy (CIN) is:

• A Use ionic high-osmolar contrast media (HOCM) at reduced volume
• B Switch to gadolinium-based MRI contrast as it does not cause nephropathy
• C No precautions needed as CIN risk is only significant when eGFR <15
• D Use iso-osmolar or low-osmolar non-ionic contrast with IV hydration (0.9% NaCl or sodium bicarbonate) and minimize contrast volume ✓

Explanation

For patients with CKD (eGFR 15-44 mL/min/1.73m²), CIN risk is elevated with iodinated contrast. Current guidelines recommend: use of iso-osmolar (iodixanol) or low-osmolar non-ionic contrast agents (lower nephrotoxicity than HOCM); adequate IV hydration with normal saline or sodium bicarbonate (1 mL/kg/hr starting 6-12h before and continuing 6-12h after); and minimizing contrast volume (use ≤100 mL where possible). Gadolinium at eGFR <30 risks nephrogenic systemic fibrosis (NSF) — not a safe alternative. Stopping nephrotoxic medications (NSAIDs, diuretics) 24-48h before is also recommended. CIN risk is clinically significant from eGFR <60 and high from <30.

Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.