Magnetic resonance imaging (MRI) is a test that uses a large magnet, radio signals, and a computer to make images of organs and tissue in the body. In this case, the heart is imaged.
The MRI machine is large and tube-shaped. It creates a strong magnetic field around the body. Some MRI machines are more open.
The magnetic field lines up the hydrogen protons in your body. The radio waves then knock the protons out of position. As they realign back into proper position, they send out radio signals. A computer receives the signals and converts them into images of the body. This image appears on a viewing monitor.
MRI may be used instead of a CT scan when organs or soft tissues are being studied.
MRI of the heart may be done to assess signs or symptoms that may suggest:
There may be other reasons for your healthcare provider to recommend an MRI of the heart.
There is no radiation exposure during MRI.
You can’t have an MRI if you have a:
If you are pregnant or think you may be, tell your healthcare provider. MRI is generally safe in pregnancy, but you and your healthcare provider should discuss the risks and benefits of having MRI. If contrast dye is used, there is a risk you could have an allergic reaction to the dye. If you are allergic to or sensitive to medicines, tell your healthcare provider. If you have kidney problems, there is a risk of a serious reaction to the dye. Discuss this risk with your healthcare provider prior to the test.
MRI contrast may have an effect on other conditions, such as allergies, asthma, anemia, low blood pressure, kidney disease, and sickle cell disease.
Nephrogenic systemic fibrosis (NSF) is a very rare but serious complication of MRI contrast use in people with kidney disease or kidney failure. If you have a history of kidney disease, kidney failure, kidney transplant, liver disease or are on dialysis, inform the MRI technologist or radiologist prior to receiving contrast.
There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your healthcare provider prior to the MRI.
You may have your MRI an outpatient basis or as part of your stay in a hospital.
Generally, an MRI follows this process:
The MRI itself causes no pain. But, having to lie still for might be uncomfortable. The technologist will use all possible comfort measures and complete the test as quickly as possible to reduce any discomfort or pain.
If you have metal fillings in your teeth, you may feel some slight tingling of the teeth during the test.
Move slowly when getting up from the scanner table to avoid any dizziness or lightheadedness from lying flat for the length of the MRI.
If you had a sedative, you need to rest until the sedatives have worn off. You will also need to avoid driving.
If contrast dye is used, you may be watched for a period for any side effects or reactions to the contrast dye, such as itching, swelling, rash, or difficulty breathing.
If you notice any pain, redness, and/or swelling at the IV site after you return home, tell your healthcare provider. It could mean you have an infection or other type of reaction.
Otherwise, there is no special type of care required after a MRI scan of the heart. You may go back your usual diet and activities, unless your healthcare provider advises you differently.
Your healthcare provider may give you other instructions after the MRI, depending on your situation.