What should I expect before cardiac magnetic resonance imaging?

You'll be asked to fill out a screening form before having cardiac MRI. The form may ask whether you have had previous surgeries, have any metal objects in your body, or have any medical devices (like a cardiac pacemaker) surgically implanted in your body.

Most, but not all, implanted medical devices are allowed near the MRI machine. Talk to your doctor or the technician operating the machine if you have concerns about any implanted devices or conditions that may interfere with the MRI.

MRI can seriously affect some types of implanted medical devices.

  • Implanted cardiac pacemakers and defibrillators can malfunction.
  • Cochlear (inner-ear) implants can be damaged. Cochlear implants are small electronic devices that help people who are deaf or who can't hear well understand speech and the sounds around them.
  • Brain aneurysm (AN-u-rism) clips can move due to MRI's strong magnetic field. This can cause severe injury.
Your doctor will let you know if you shouldn't have a cardiac MRI because of a medical device. If this happens, consider wearing a medical ID bracelet or necklace or carrying a medical alert card that states that you shouldn't have an MRI.

Your doctor or technician will tell you whether you need to change into a hospital gown for the test. Don't bring hearing aids, credit cards, jewelry and watches, eyeglasses, pens, removable dental work, and anything that's magnetic near the MRI machine.

Tell your doctor if being in a fairly tight or confined space causes you anxiety or fear. This fear is called claustrophobia (klaw-stro-FO-be-a). If you have this condition, your doctor might give you medicine to help you relax. Your doctor may ask you to fast (not eat) for 6 hours before you take this medicine on the day of the test.

Some newer cardiac MRI machines are open on all sides. Ask your doctor to help you find a facility that has an open MRI machine if you're fearful in tight or confined spaces.

This answer from the National Heart, Lung and Blood Institute has been reviewed and/or edited by Dr. William D. Knopf.

Here's what happens when you arrive for a cardiac stress magnetic resonance imaging (MRI) test:
  • Checking in. Tell the MRI technologist if you have any electronic devices or surgical implants in your body.
  • Getting ready. You'll change into a gown and remove glasses, removable dental work, and any other metal items. Patches will be attached to your chest to monitor your heartbeat.
  • IV line. An intravenous (IV) line will be placed in your wrist or arm so medication and MRI enhancing agent can be injected into a blood vessel during the test.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.