What is a Cardiac MRI?
A cardiac MRI (CMR) test is an evaluation of your heart using a specialized MRI camera. The test provides a very accurate assessment of your heart’s structure and function, as well as an evaluation of the status of the major blood vessels within your chest. With the injection of contrast (gadolinium), information can be obtained about the blood supply to your heart, and about the amount of heart muscle scarring, if any.
Common Reasons to Have this Test
- To investigate further any structural abnormalities or unusual findings noted on other heart imaging tests.
- To monitor heart muscle thickness and function, and heart size in conditions that require repeat interval assessments of these parameters (eg. valve disease, cardiomyopathy, chemotherapy, ect.).
- To assess if heart function may be improved with bypass surgery or angioplasty in patients with previous heart muscle damage (ie. from a heart attack).
- To evaluate the structures immediately around the heart (eg. aorta, pericardium, pulmonary arteries, etc.)
Preparing for the Test
You should fast for at least three hours prior to your exam, in case contrast injection is required (not all CMR tests require contrast injection, but the need to use contrast is not always known prior to the start of the study). Unless instructed otherwise by your physician, continue to take your usual medications as prescribed. Because a few electrodes will need to be attached to your chest, and because you will be instructed to change into a gown, wear clothing that allows you to get undressed easily from the waist up.
The actual test will take approximately one and a half hours. You will change into a gown and remove all metallic objects (such as watches, jewelry, belts, etc.). Electrodes will be attached to your chest to monitor your heart rhythm. You will lie down on an imaging table and a special imaging coil will be secured over your chest. You will then be moved into the MRI scanner (your head will be inside the scanner). You healthcare providers will make you as comfortable in the scanner as possible, and can provide you with earphones to listen to music (radio station of your choice, or a personal CD if you would like to bring one in). Most of the time, you will be lying quietly in the scanner. Intermittently you will be asked to hold your breath for several seconds while MR pictures are taken of your heart.
The actual time in the scanner can range from 30 minutes to one hour. After all the pictures are acquired, the electrodes will be removed and you will be free to go home. If your particular examination requires contrast injection, an I.V. will be started (either before or sometime during the examination), and contrast will be injected when required. The I.V.will be removed before you leave.
Is It Safe?
A cardiac MRI test is very safe. There is no radiation exposure, and side effects are very rare. Sometimes people can feel anxious or even claustrophobic inside the scanner. This in not dangerous, but can be uncomfortable. Closing your eyes and concentrating on the music while in the scanner is helpful. The technician will be in constant contact with you, and will let you know what is happening and what to expect as the test is taking place. If required, we can provide you with medications to help you relax. Gadolinium injection is very safe with a very low risk of side effects.
When Will I Receive the Results?
Your test will be reviewed and interpreted by a cardiologist and a report will be provided to your physician who will contact you.