What type of contrast agent is used for MR imaging, and what risk must be considered in CKD?

• A. Gadolinium-based contrast; risk of nephrogenic systemic sclerosis in CKD.
• B. Iodinated contrast; risk of contrast-induced nephropathy.
• C. Gadolinium-based contrast; risk of allergic reactions in CKD.
• D. Iron oxide contrast; risk of iron overload.

Answer: (A)

Gadolinium-based contrast agents are used to enhance MR images by improving tissue and vascular contrast. In patients with reduced kidney function, the main concern is nephrogenic systemic fibrosis, a rare but serious condition linked to gadolinium exposure in CKD. This is why the combination of gadolinium-based contrast with the specific CKD risk is the best match.

Iodinated contrast is typically used with CT and carries a risk of contrast-induced nephropathy, not primarily an MR issue. Iron oxide contrast is not common today, and its main concern is not CKD-related fibrosis. Allergic reactions can occur with gadolinium, but in CKD the standout risk that drives practice is nephrogenic systemic fibrosis.