Cardiac MRI

What is a cardiac MRI?

MRI stands for magnetic resonance imaging. An MRI scanner is a device that uses a powerful magnet and radio waves to make pictures of the inside of your body.

A cardiac MRI is a test that uses an MRI scanner to take pictures of your heart. Your doctor can look at these pictures to get important information about the structure and function of your heart, if your heart has any scars, and how well blood is flowing to your heart.

Why do I need a cardiac MRI?

Your doctor has performed other tests and has decided that a cardiac MRI will provide information that other tests can’t provide.

What happens during a cardiac MRI?

Before the test begins, a substance called contrast is injected into your vein. Contrast helps to improve the images that the MRI scanner takes of your body.

You will lay inside the MRI scanner for about an hour. You will need to stay still through the whole test. Sometimes you will be asked to hold your breath to help keep your body still.

Some people who are uncomfortable in small spaces may feel claustrophobic when they’re in the scanner. If you have claustrophobia, you should consider discussing this with your physician in advance. A relaxing medicine like valium can help you stay calm during the test.

How much radiation will I get from a cardiac MRI?

None. MRI does not expose you to ionizing radiation.

Does the contrast used during a cardiac MRI affect my kidney function?

No. The contrast used in an MRI does not cause kidney problems.

I’m allergic to CT contrast. Does that mean I’m also allergic to MRI contrast?

No. CT contrast is different from MRI contrast. If you are allergic to CT contrast, that doesn’t mean you are allergic to MRI contrast.

There is a very slight risk of an allergic reaction to MRI contrast. The reaction is usually mild and can easily be controlled with medication. If you have allergic symptoms, you can ask for immediate assistance during the test.

What happens after the cardiac MRI?

You can go home immediately after the test.

If you were given medication to help you relax during the scan, you will not be allowed to drive. You’ll need someone to drive you home.

I have a pacemaker or defibrillator. Can I get a cardiac MRI?

It depends on your type of pacemaker or defibrillator. Some pacemakers or defibrillators can be scanned. Check with your cardiologist about your type of device. 

I am pregnant and my doctor wants me to have a cardiac MRI. Is this safe during pregnancy?

Multiple scientific studies have shown that the risks for the fetus are very low.

An MRI is also safer than other types of image scans that use radiation. MRI doesn’t expose the fetus to ionizing radiation.

There is some risk to the fetus when contrast is used during the scan. Contrast is not recommended for use in pregnant patients unless the potential benefit of using it justifies the potential risk to the fetus. If you’re pregnant, you should discuss this with your cardiologist.

What should I know about choosing where to go for a cardiac MRI?

Cardiac MRI is a highly specialized procedure. It’s important to choose a facility that has the best equipment and has technicians and physicians who have received special training to perform the procedure.

The University of Iowa is one of the few centers in the United States that has cardiologists and radiologists specifically trained in cardiac MRI.

Our staff has the training to:

  • Review your medical history before the test to make sure the test will be performed in the shortest possible time to get the proper information
  • Perform the test on our state-of-the-art MRI scanning equipment
  • Read the results of the test in a way that gets the information your cardiologist will need to create the best treatment plan for you
Last reviewed: 
November 2019
Alternative Names: 
Cardiac magnetic resonance imaging

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