Gadolinium-based contrast agents (GBCAs) are used for MRI. Nephrogenic systemic fibrosis (NSF) is a severe complication of GBCAs in patients with renal failure. Which physicochemical property of the GBCA is MOST closely associated with the risk of NSF?
- A Osmolality of the contrast agent
- B Thermodynamic and kinetic stability of the gadolinium chelate — linear ionic agents are highest risk, macrocyclic agents are lowest risk ✓
- C The dose of iodine co-administered
- D Molecular weight of the gadolinium complex
Correct answer: B. Thermodynamic and kinetic stability of the gadolinium chelate — linear ionic agents are highest risk, macrocyclic agents are lowest risk
Explanation
NSF risk correlates with the stability of the gadolinium chelate: if the chelate dissociates and releases free gadolinium ions, these deposit in tissues causing fibrosis. Linear (open-chain) GBCAs — both ionic (e.g., gadopentetate/Magnevist) and non-ionic (e.g., gadodiamide/Omniscan) — have lower thermodynamic and kinetic stability, higher transmetalation risk, and highest NSF risk. Macrocyclic GBCAs (e.g., gadoteridol/ProHance, gadobutrol/Gadovist) have caged cage-like structure, are most stable, and have the lowest NSF risk.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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