Hospital  >  Departments  >  Medical Imaging  >  Magnetic Resonance Imaging (MRI)
Share:  
|
PAGE
MENU

Magnetic Resonance Imaging (MRI)

What is magnetic resonance imaging?

Magnetic resonance imaging (MRI) produces detailed images of the body using a very strong magnet and radio waves. It does not use radiation. The part of the body being examined is centred inside a tunnel that creates a magnetic field. Since our bodies are mostly made up of water, when we lie down in a strong magnetic field, the hydrogen atoms in the water “line up” with the magnetic field, much like a compass pointing north. Radio waves cause the atoms to emit signals that a computer will measure and create pictures of the body part being examined.

Person getting an MRI

While MRIs are generally safe, the magnet used during the test means people with certain implanted devices, such as pacemakers or cochlear implants, may not be able to have the test. Alternative imaging should be discussed with your doctor.

Getting an MRI: what to expect

Preparing for the test

Different tests require different preparations. It’s very important the correct preparation is used for the test to be performed properly. For example, an abdominal or pelvic scan may require you to not eat or drink for six hours before your test. Another test may not have any restrictions.

If you are scheduled to have an MRI at Sunnybrook and are not sure of how to prepare for it, please call 416-480-4336.

If you are concerned about closed spaces, discuss with your doctor the possibility of getting a prescription for oral sedation that you will take after you arrive for your test to help relax you. However, most patients who are nervous do not end up taking sedation after speaking with our technologists. We’ll do our best to keep you comfortable.

You may require blood tests beforehand to determine how well your kidneys are working – a process that can delay your scan by about 30-60 minutes but will ensure that it is safe for you to receive the contrast injection.

» Watch the video: How to prepare for an MRI scan

On the day of the test

The test will take approximately one to two hours, including time to prepare.

Please check-in for your appointment at the Bayview Campus (2075 Bayview Ave), A-wing, ground floor, room AG 256.

After check-in, you’ll be taken to a room to prepare for the test. Our staff will ask you a number of questions, including your medical history, current medications and allergies. You can also ask any questions you may have about the procedure.

You will be asked to remove your watch, jewelry, wallet (credit cards with magnetic strips can be erased by the magnet), and any clothing with zippers, clasps or wires that may interfere with the MRI. You may be asked to wear a hospital gown during the scan.

During the test

The technologist will help you lie in the correct position on the examining table. The table will then be positioned into a five-foot long tunnel so that the body part being scanned is in the centre. Depending on the scan, a good portion of your body may be outside of the tunnel.

The scan can be loud, so you’ll be given hearing protection. As the MRI scan begins, you will hear the equipment making a muffled thumping sound. You shouldn’t experience any pain with this test, however you may feel a little warm.

It is important that you lie as still as possible during the procedure so that your images are as clear as possible.

» Read tips for managing clastrophobia during your MRI scan

After the test

Generally, you can resume your usual activities and regular diet immediately after the test. If you have taken a sedative, you must have a friend or family member drive you home.

The results of your magnetic resonance imaging should be available to your referring physician within 10 business days after your test. Your physician will discuss the test results with you.

Your report can also be accessed through MyChart in two to three weeks after your test.

MyChart

Stay connected to your health information

Questions? Learn more

Location and contact

Magnetic Resonance Imaging (MRI)

Sunnybrook Health Sciences Centre
2075 Bayview Avenue,
A-wing, ground floor, room AG 256
Toronto, ON M4N 3M5

Phone: 416-480-6177

MRI services are available at our Bayview Campus by pre-scheduled appointment only.

Refer a patient

» Referral information