What happens during the test?
During the test, a person removes their clothes and dresses in a paper gown. They lie face-up on a table that is part of the MRI scanner. The table slides into a narrow tunnel that contains the magnet, and the part of the body that is being examined is moved into the center of the magnet. An MRI test usually lasts between 15 to 90 minutes.
The machine makes loud noises for minutes at a time during the test. This may be disturbing for some people. If you are bothered by loud noises, try wearing earplugs for the test. It is extremely important to remain still to achieve the most accurate images possible.
Before the test starts, you should be given a button to press that alerts the technologist if you become too uncomfortable at any point during the test. If you are very tense, your doctor may prescribe a sedative for you to take before the test.
How should I prepare for this test?
If your doctor tells you that you need to have an MRI, there are certain things you'll be asked about before having the test. Tell your doctor if you:
- are uncomfortable in small spaces
- have a pacemaker, artificial heart valve, artificial limb, cochlear implant, dental implants, metal implants or pins, or any other implanted or prosthetic medical device
- have worked in areas with metal, such as in factories
- are pregnant, or think you might be pregnant
- have an allergy of any kind (the dyes used during MRIs could cause serious allergic reactions in some people with pre-existing allergies including those involving hay fever, hives, or asthma, as well as food or medication allergies)
- have an intrauterine device (IUD)
- have a medication patch on your skin (the patch may burn during the test if not removed)
- have any medical conditions (people with certain conditions should not use the MRI test dyes)
You will need to remove all metal objects including hearing aids, dentures, jewellery, and hairpins. Otherwise, these objects will be attracted to the powerful magnet used during the MRI.
Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any medication allergies and medical conditions that you may have.
Ask your doctor or pharmacist whether you need to stop taking any of your medications before the test.
What can I expect after the test?
The radiologist might discuss preliminary results of the test after it's complete. No pain or other sensations normally occur after an MRI. You can return to your usual activities once the test is complete.
Results
A radiologist reviews and interprets the images from an MRI scan. Full results are usually available a couple of days later, and your doctor will discuss these results both with the radiologist and you.