Cardiac MRI can provide detailed information about the type and severity of the heart disease to help your doctor decide the best way to treat heart problems, such as coronary artery disease, heart valve problems, pericarditis, heart tumors, or damage from a heart attack. Cardiac MRI can help explain the results of other imaging tests, such as chest X-rays and chest CT scans.

Cardiac MRI can be performed in a medical imaging facility or in a hospital. Before your procedure, a contrast dye may be injected to accentuate your heart and blood vessels in a vein in your arm. You may feel discomfort from the needle or a cool feeling when the contrast dye is injected. The MRI machine is a large, tunnel-like machine with a table. You lie still on the table and the table slides into the machine. You will hear loud humming, tapping and buzzing when you are inside the machine while pictures of your heart are being taken. You can listen to and talk to the technician conducting the test while in the machine. The technician may ask you to hold your breath for a few seconds during the test.

Cardiac MRI has few risks. In rare cases, the contrast dye can harm people with kidney or liver disease or cause an allergic reaction. Researchers are investigating whether multiple injections of contrast dye, defined as four or more, can cause other adverse effects. Discuss with your doctor and the technicians conducting the test whether you are or might be pregnant. Let your doctor know if you are breastfeeding as the contrast dye can pass into your breast milk. If you need to have the contrast dye injected, you may want to pump and keep enough breast milk for one to two days after your test, or you can bottle-feed your baby during that time. Tell your doctor if you have:

• A pacemaker or other implanted device, as the MRI device can damage these devices.
• Metal in your body from previous surgeries as it can interfere with the MRI machine.
• Metal on your body from piercings, jewelry, or some transdermal skin patches, as these can interfere with the MRI machine or cause burns. Tattoos can cause a problem because older tattoo inks can contain small amounts of metal.