Heart Disease and MRI Testing
One test used for evaluation of heart disease is MRI (magnetic resonance imaging). MRI uses large magnets and radio-frequency waves to produce pictures of the body's internal structures; no X-ray exposure is involved. This technique obtains information about the heart as it is beating, creating images of the heart throughout its pumping cycle.
Why Do I Need a MRI Scan?
Your doctor uses the MRI to evaluate the anatomy and function of the structures of the chest, including the heart, lungs, major vessels, and pericardium (the outside lining of the heart). It is also used to determine the presence of diseases such as coronary artery disease, pericardial disease, cardiac tumors, heart valve disease, heart muscle disease (cardiomyopathy), and congenital heart disease.
How Should I Prepare for a MRI Scan?
If you are not claustrophobic (have a fear of closed spaces), you will not require any sedation before the MRI scan. Eat as usual and take your medications as usual.
If you are claustrophobic, you may ask your doctor to give you a sedative (a medication to help you relax) before your MRI. If you take a sedative, you should not eat any solid food for six hours prior to receiving your sedative to avoid nausea. You may have clear liquids (apple juice, Jell-O, black coffee, tea, or water) up to two hours prior to taking the sedative. You may take your regular medications (with sips of water) unless your doctor advises against it. Make arrangements for transportation home since you will likely still be drowsy from the sedative.
The MRI uses powerful magnets to create its images. For your safety, anyone undergoing a scan should be free of any metallic or magnetic items. Inform the MRI staff if you have any metallic implants or any metal under the skin. Most metallic implants, such as sternal wires and clips used for heart surgery, pose no problem.
Some conditions may make an MRI inadvisable. Tell your doctor if you have any of the following conditions:
- Implanted pacemaker or defibrillator
- Older model Starr-Edwards (metallic ball/cage type) heart valve implant
- Cerebral aneurysm clip (metal clip in a blood vessel in the brain)
- Implanted insulin pump, narcotic pump, or implanted nerve stimulators (TENS) for back pain
- Metal in the eye or eye socket
- Cochlear (ear) implant for hearing impairment
Wear a shirt or blouse that can be easily removed. Women should wear a bra that can be easily removed prior to the MRI. Wear metal-free pants, such as sweatpants with elastic bands, during the test. A gown will be provided. Please do not wear or carry any of the following: belt buckles, metal zippers, snaps, watches, or wallets with bank or credit cards with magnetic strips.