MRI, or magnetic resonance imaging, uses a strong magnetic field and radio waves to produce a detailed image of the heart, lungs, and surrounding areas of the chest.
MRI’s Diagnostic Capabilities
An MRI can diagnose a number of abnormalities of the heart, including coronary artery disease, pericardial disease, cardiac tumors, heart valve disease, heart muscle disease (also called cardiomyopathy), and congenital heart disease.
Preparing for the Test
If your doctor orders an MRI, he will give detailed instructions on how to prepare for it. In general, you can eat or drink with no problems.

Because an MRI scanner is a long tube you will be passing through, if you are claustrophobic you may want to ask your doctor for a sedative to help you relax during the test, as anxiety and hyperventilation can disrupt the accuracy of the test. If you take a sedative, you should not eat any solid food for six hours prior to receiving your sedative to avoid nausea, although you can have clear liquids.

The MRI scanner utilizes strong magnets, so anything magnetic should be removed before the test. In some cases, people with the following devices or conditions should not receive an MRI. These conditions include:
– An implanted pacemaker or defibrillator.
– Pregnancy.
– An Implanted insulin pump, narcotic pump or implanted nerve stimulators
– Metal in the eye or eye socket.
– A hearing aid.
– Any metal rods in the body.
What to Expect
During the test, you will be asked to change into a hospital gown and lay on a bed that will pass through the scanner. The doctor or technician will place electrodes that monitor the heart’s activity on your chest. You will probably receive an IV as well, so a special dye that helps the doctor see the heart and its surrounding more clearly can be injected.

For the MRI scan itself, you will lie on a hospital bed that will pass through the MRI scanner. The entire process takes between 30 and 75 minutes, and it is important you hold as still as possible. You may be asked to hold your breath periodically to prevent the image from being blurred.

MRIs and Safety
The MRI does not use radiation and no x-ray exposure is involved. Even so, it is recommended that pregnant women avoid undergoing an MRI unless absolutely necessary.

During the test, the MRI machine will cause loud noises and vibrations that result from the switching of magnetic fields. The noises can be so loud, in fact, they can reach the equivalent of a jet taking off. For this reason, the doctor will give you ear plugs to soften the noise as well as reduce anxiety, and they should be worn.

Anxiety may result from an MRI, usually from calustrophobia. The MRI scanner itself is a long, narrow tube, so people who experience claustrophobia should discuss with their doctor the options available to make the test as anxiety free as possible. He may give you a mild sedative for relaxation, but for people with severe claustrophobia, ahesthesia may be required.

An MRI is sometimes ordered by the doctor to help diagnose a variety of coronary problems. These can include coronary artery disease as well as damage to the heart and its surrounding areas. Once the MRI is completed, the doctor will discuss its results with you and decide on a treatment plan from there.