Navigate Up

Full Library - A-Z Index


Print This Page

Heart MRI

Heart magnetic resonance imaging (MRI) is an imaging method that uses powerful magnets and radio waves to create pictures of the heart. It does not use radiation (x-rays).

Single MRI images are called slices. The images can be stored on a computer or printed on film. One exam produces dozens or sometimes hundreds of images.

The test may be done as part of a chest MRI .

Alternative Names

Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart

How the Test is Performed

You may be asked to wear a hospital gown or clothing without metal fasteners (such as sweatpants and a t-shirt). Some types of metal can cause blurry images.

You will lie on a narrow table, which slides into a large tunnel-like tube.

Some exams require a special dye (contrast). The dye is most often given before the test through a vein (IV) in your hand or forearm. The dye helps the radiologist see certain areas more clearly.

During the MRI, the person who operates the machine will watch you from another room. The test most often lasts 30 - 60 minutes, but may take longer.

How to Prepare for the Test

You may be asked not to eat or drink anything for 4 - 6 hours before the scan.

Tell your doctor if you are afraid of close spaces (have claustrophobia). You may be given a medicine to help you feel sleepy and less anxious, or your doctor may suggest an "open" MRI, in which the machine is not as close to the body.

Before the test, tell your health care provider if you have:

  • Brain aneurysm clips
  • Certain types of artificial heart valves
  • Heart defibrillator or pacemaker
  • Inner ear (cochlear) implants
  • Kidney disease or dialysis (you may not be able to receive contrast)
  • Recently placed artificial joints
  • Certain types of vascular stents
  • Worked with sheet metal in the past (you may need tests to check for metal pieces in your eyes)

Because the MRI contains strong magnets, metal objects are not allowed into the room with the MRI scanner:

  • Pens, pocketknives, and eyeglasses may fly across the room.
  • Items such as jewelry, watches, credit cards, and hearing aids can be damaged.
  • Pins, hairpins, metal zippers, and similar metallic items can distort the images.
  • Removable dental work should be taken out just before the scan.

How the Test will Feel

A heart MRI exam causes no pain. Some people may become anxious when inside the scanner. If you have a hard time lying still or are very anxious, you may be given medicine to relax. Too much movement can blur MRI images and cause errors.

The table may be hard or cold, but you can ask for a blanket or pillow. The machine produces loud thumping and humming noises when turned on. You may get ear plugs to help reduce the noise.

An intercom in the scanner allows you to speak to the person operating the exam at any time. Some MRI scanners have televisions and special headphones to help pass the time.

There is no recovery time, unless sedation was necessary. (You will need someone to drive you home if sedation was given.) After an MRI scan, you can resume your normal diet, activity, and medicines, unless your doctor tells you otherwise.

Why the Test is Performed

MRI provides detailed pictures of the heart and blood vessels from many views. Often, it is used when more information is needed after you have had an echocardiogram or heart CT scan. MRI is more accurate than CT scan or other tests for certain conditions, but less accurate for others.

Heart MRI may be used to evaluate or diagnose:

  • Heart muscle damage after a heart attack
  • Birth defects of the heart
  • Heart tumors and growths
  • Weakening or problems with the heart muscle
  • Symptoms of heart failure

What Abnormal Results Mean

Abnormal results may be due many things, including:

  • Heart valve disorders
  • Fluid in the sac-like covering around the heart (pericardial effusion )
  • Tumor of the blood vessels or around the heart
  • Atrial myxoma
  • Congenital heart disease (heart problem that you are born with)
  • Damage or death to the heart muscle, seen after a heart attack
  • Inflammation of the heart muscle
  • Infiltration of the heart muscle by unusual substances
  • Weakening of the heart muscle, which can be caused by sarcoidosis or amyloidosis

Risks

There is no radiation involved in MRI. The magnetic fields and radio waves used during the same have not been shown to cause any significant side effects.

Allergic reactions to the dye used during the exam are rare. The most common type of contrast (dye) used is gadolinium. It is very safe. The person operating the machine will monitor your heart rate and breathing as needed. Rare complications can occur in patients with severe kidney problems.

People have been harmed in MRI machines when they did not remove metal objects from their clothes or when metal objects were left in the room by others.

MRI is most often not recommended for traumatic injuries. Traction and life-support equipment cannot safely enter the scanner area.

MRIs can be costly, take a long time to perform, and are sensitive to movement.

References

Kwong RY. Cardiovascular magnetic resonance imaging. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 18.

Kramer CM, Beller GA. Noninvasive cardiac imaging. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 56.

Updated: 5/13/2014

Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.


©  UPMC | Affiliated with the University of Pittsburgh Schools of the Health Sciences
Supplemental content provided by A.D.A.M. Health Solutions. All rights reserved.

For help in finding a doctor or health service that suits your needs, call the UPMC Referral Service at 412-647-UPMC (8762) or 1-800-533-UPMC (8762). Select option 1.

UPMC is an equal opportunity employer. UPMC policy prohibits discrimination or harassment on the basis of race, color, religion, ancestry, national origin, age, sex, genetics, sexual orientation, marital status, familial status, disability, veteran status, or any other legally protected group status. Further, UPMC will continue to support and promote equal employment opportunity, human dignity, and racial, ethnic, and cultural diversity. This policy applies to admissions, employment, and access to and treatment in UPMC programs and activities. This commitment is made by UPMC in accordance with federal, state, and/or local laws and regulations.

Medical information made available on UPMC.com is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have. Further, UPMC.com is not a tool to be used in the case of an emergency. If an emergency arises, you should seek appropriate emergency medical services.

For UPMC Mercy Patients: As a Catholic hospital, UPMC Mercy abides by the Ethical and Religious Directives for Catholic Health Care Services, as determined by the United States Conference of Catholic Bishops. As such, UPMC Mercy neither endorses nor provides medical practices and/or procedures that contradict the moral teachings of the Roman Catholic Church.

© UPMC
Pittsburgh, PA, USA UPMC.com