MRI With Contrast: What Is Gadolinium and Is It Safe?

If your doctor ordered an MRI "with contrast" or "with and without contrast," you'll receive an injection of a gadolinium-based contrast agent. Here's what you need to know about this important diagnostic tool.

What Is Gadolinium?

Gadolinium is a rare earth metal that, when chemically bonded to a carrier molecule, creates an MRI contrast agent. When injected intravenously, it enhances certain tissues on MRI images by altering how they respond to the magnetic field.

Important: MRI contrast (gadolinium) is completely different from CT contrast (iodine). If you're allergic to CT contrast or shellfish, that does not mean you'll react to gadolinium.

Why Is MRI Contrast Used?

Gadolinium helps radiologists: - Detect tumors — many tumors "light up" after contrast injection - Distinguish scar tissue from active disease — critical after surgery or treatment - Evaluate blood vessels (MR angiography) - Assess inflammation — in the brain, spine, joints, or organs - Characterize lesions — helps determine if a finding is benign or concerning

Common exams that use gadolinium include brain MRI (for tumors, MS, infection), spine MRI (for disc disease, tumors), breast MRI (high-risk screening), liver and abdominal MRI, and cardiac MRI.

Is Gadolinium Safe?

For the vast majority of patients, gadolinium is very safe. It has been used in hundreds of millions of MRI exams worldwide since the 1980s.

Allergic Reactions True allergic reactions are rare (0.07-2.4% of patients). Most are mild: hives, itching, or nausea. Severe anaphylaxis is extremely uncommon.

Kidney Concerns (NSF) In patients with **severe kidney disease** (GFR below 30), an older class of gadolinium agents was associated with a rare condition called Nephrogenic Systemic Fibrosis (NSF). Modern "Group II" agents (which we use at AMI) have virtually eliminated this risk. If you have kidney disease, your kidney function will be checked before contrast is given.

Gadolinium Retention Research has shown that trace amounts of gadolinium can remain in the brain and body after injection. Currently, there is **no evidence** this causes any harmful effects. The FDA has reviewed the data and concluded that the benefits of gadolinium contrast outweigh the theoretical risks. However, contrast is only used when medically necessary.

What to Expect

1. An IV line is placed in your arm before or during the scan
2. The first set of images is taken without contrast
3. Gadolinium is injected through the IV — you may feel a cool sensation
4. A second set of images is taken after injection
5. Total exam time: 45-75 minutes for a with-and-without study

Unlike CT contrast, gadolinium typically causes no warm flush or metallic taste.

After the Exam

• The gadolinium is cleared by your kidneys within 24 hours (in patients with normal kidney function)
• Drink extra water to help flush it
• Resume all normal activities immediately

Questions About Your MRI?

Call us at (727) 398-5999. Our MRI technologists are happy to address any concerns about contrast or the scan itself.