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.
Carotid artery disease is also called carotid artery stenosis. The term refers to the narrowing of the carotid arteries. This narrowing is usually caused by the buildup of fatty substances and cholesterol deposits, called plaque. Carotid artery occlusion refers to complete blockage of the artery. When the carotid arteries are obstructed, you are at an increased risk for a stroke, the third leading cause of death in the U.S.
If you are not claustrophobic (have a fear of closed spaces), you will not require any sedation to have an MRI test. 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. To avoid nausea, you should not eat any solid food for six hours prior to receiving your sedative. 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 exam. 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.