Cardiac MRI

What is magnetic resonance imaging (MRI) of the heart?

MRI is a noninvasive test that uses a large magnet, radio signals and a computer to make images of organs and tissues in the body; in this case, the heart.

Why might I need an MRI of the heart?

MRI of the heart may be done to assess the heart’s chambers size and function, thickness and movement of the walls of the heart, the extent of damage caused by a heart attack or heart disease, structural problems in the aorta, such as aneurysm or dissection, inflammation or blockages in the blood vessels. There may be other reasons for your health care provider to recommend an MRI of the heart.

What are the risks of a MRI of the heart?

There is no radiation exposure during MRI. You can’t have an MRI if you have a:

  • Pacemaker
  • Older intracranial aneurysm clips
  • Cochlear implants
  • Certain prosthetic devices (such as artificial joints)
  • Implanted medicine infusion pump
  • Neurostimulator
  • Bone growth stimulator
  • Certain intrauterine contraceptives (IUDs)
  • Other iron-based metal implants
  • Bullet or shrapnel

If you are pregnant or think you may be, tell your health care provider. MRI is generally safe in pregnancy but you and your provider should discuss the risks and benefits. Contrast dye may be used; there may be a risk of an allergic reaction to the dye. If you are sensitive to medicines tell your healthcare provider. If you have kidney problems, there is risk of a serious reaction to the dye. MRI contrast may have an effect on conditions such as allergies, asthma, anemia, low blood pressure, kidney disease, or sickle cell disease. There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your health care provider prior to the MRI.

How do I prepare for an MRI?

  • You may eat, drink and take medications as usual.
  • You must change into a patient gown. Please remove all piercings along with any items that might contain metal, leave all jewelry and valuables at home.
  • If you require anti-anxiety medication due to claustrophobia, contact your ordering physician. Please note with this medicine you will need someone to drive you home.
  • If you have metal in your body that was not disclosed prior to your appointment your study may be delayed, rescheduled or cancelled upon your arrival.
  • Based on your medical condition your health care provider may require other specific preparation.

What happens during an MRI of the heart?

Generally, an MRI follows this process:

  • Remove any clothing jewelry, eyeglasses, hearing aids, hairpins, removable dental work, or other objects that may interfere with the MRI.
  • If you are asked to remove clothing, you will be given a gown to wear.
  • If you are to have a MRI done with contrast, you will have an intravenous (IV) line in the hand or arm to inject the contrast dye.
  • You will lie on a scan table that slides into a large circular opening of the scanning machine. You will lie down for 30 to 60 minutes. 
  • It’s important to remain very still during the test. Any movement could affect the quality of the scan.
  • You may be told to hold your breath, or to not breathe, for a few seconds. You will then be told when you can breathe.
  • You will be given earplugs or a headset to wear to help block out the noise from the scanner. You may be able to listen to music.
  • During the scanning process, a clicking noise will sound as the magnetic field is created and pulses of radio waves are sent from the scanner.
  • If contrast dye is used you may feel effects as the dye is injected into the IV line that include coolness or discomfort that should only last a few seconds.
  • If you have metal fillings in your teeth, you may feel some slight tingling in your teeth during the test.
  • The MRI itself causes no pain. But, having to lie still for so long might be uncomfortable. 

What happens after an MRI of the heart?

  • If you were given a sedative you will not be allowed to drive.
  • If contrast dye is used you may be watched for a period for any side effects or reactions to the dye.
  • When the test is complete, a credentialed physician will review your results and enter them into your electronic medical record. Your primary physician will then be notified of the results. The testing staff will be unable to provide you with your results.