Magnetic Resonance Imaging (MRI)

We use a strong magnetic field and radio waves to create detailed images of the organs and tissues in your body.

What we do

Magnetic resonance imaging (MRI) uses a strong magnet and radio waves to create detailed images of your organs and tissues. This helps physicians diagnose and monitor diseases and injuries.

MRI machines look like a tunnel with openings at both ends. There is plenty of air and light inside the machine. During the MRI, you will lie on an examination table that will slide into the machine, either head or feet first, depending on what is being examined.

The MRI machine uses magnets and radio waves to create a cross-sectional image or “slices” of the body part being examined. These images take longer to make compared to X-rays, CT scans or ultrasounds.

Our department offers the following types of MRI exams:

Neurological MRI for the brain, spine, head and neck
Musculoskeletal MRI (including arthrograms) for bones and joints
Abdominal or pelvic MRI for small bowel and fetal exams
Breast MRI for breast tissue
Cardiac MRI for hearts (offered at Toronto General Hospital for inpatients only)

What to expect

Before your appointment

It is important to arrive on time for your MRI appointment. If you are more than 15 minutes late, we may need to reschedule your appointment because we have MRI appointments scheduled 24 hours a day.

Avoid wearing makeup, as some makeup contains metal which can interfere with the MRI machine.

If you are anxious about tight spaces, or claustrophobic, talk to your physician before your MRI appointment. You may be able to take a calming medicine before the exam. If you do so, you will need someone to take you home.

You will need to stay still for about 30 minutes during the exam because movement can blur the images. While our technologist will do our best to make you as comfortable as possible during your exam, please tell your referring physician if holding still for long periods of time is difficult for you.

If you require a patient lift to get from a wheelchair to a bed, or if you require more than one person to assist you when getting on and off a bed, please let our office know ahead of your appointment.

In some cases, you might need to be injected with an MRI contrast dye before your exam. Contrast dye helps enhance the appearance of certain tissues or blood vessels. It is usually safe, but there is a small risk of allergic reaction. If you know you are allergic to contrast dye, or if you have a kidney condition, please let your referring physician know before coming for your MRI.

The dye is injected into a vein in your arm, except for joint exams (arthrograms) where it is injected into the joint. If health-care workers have had difficulties finding your veins for injections in the past, please let us know ahead of your appointment.

Check your appointment letter for any additional preparation instructions. If you are not properly prepared, we may need to reschedule.

If you wish to have a physician other than your referring physician copied on the results report, please let the receptionist know before your test.

At your appointment

How long your MRI will take depends on the type of MRI you are having. Usually, it takes one to two hours.

You will spend about 30 minutes filling out a health questionnaire and speaking with the technologist. The actual MRI scan can take between 30 and 90 minutes.

Our team tries to stay on time, but your appointment may be delayed by unforeseen circumstances. It is a good idea to be prepared in case your appointment runs late.

You will need to take off all clothes and jewelry before your exam, and you will be given a hospital gown to put on. Metal objects near the machine can move with enough force to cause injury. Also, the radio waves can cause some metals to heat up and cause burns inside the scanner. So, it is very important to remove all metal items, including jewelry, clothing with metal fibres (such as some yoga pants) and even some makeup.

The MRI machine makes loud noises during your exam. We will give you earplugs and headphones to help protect your hearing.

After your appointment

A report will be sent to your physician within 10 days.

What to bring

Health (OHIP) card or valid health-care coverage
A list of your current medications or supplements
A bag to store your personal belongings
Wear loose, comfortable clothing
A support person to bring you home, if needed

How to access our services

You need a referral from a health-care provider to be seen at medical imaging. Visit our referral criteria for more information.

Location

Department of Medical Imaging
600 University Avenue
5th floor

Directions

See maps, directions and parking for Mount Sinai Hospital.

Contact

Phone: 416-586-4800 ext. 4941
Fax: 416-586-4797

Hours

Contact hours
Monday to Friday
8:30 a.m. to 10:30 p.m.

Phone lines are open 24 hours Tuesday to Thursday.

Saturday to Sunday
8 a.m. to 11 p.m.

Closed for lunch
12 p.m. to 1 p.m.

Appointment hours
Monday to Friday
7:30 a.m. to 11 p.m.

24-hour appointments Tuesday to Thursday.

Saturday to Sunday
7:30 a.m. to 11 p.m.

Types of MRIs

Breast MRI

Breast MRIs are tests that examine your breast tissue. During the test, you will lie face down on a slightly raised platform on the MRI table. Your breasts will hang down between the platform and the table, and your arms will be by your sides.

You can eat and drink normally before a breast MRI. Talk to your referring physician ahead of time if you take any medications.

The exam usually takes about 30 minutes.

Musculoskeletal MRI

Musculoskeletal MRIs examine joints, soft tissues and bones.

During most of the exam, you will lie on your back with your arms at your sides. However, if it your elbow, forearm or wrist is being examined, you might need to lie on your side or stomach with your arm above your head. If that sounds difficult for you to do, talk to your referring physician before the exam.

If you are getting an arthrogram, please check your appointment letter for more detailed instructions.

You can eat and drink normally before a musculoskeletal MRI. Let your referring physician know ahead of time about any medications you are taking.

The exam can take anywhere from 30 minutes to over an hour.

Abdominal MRI

Abdominal MRIs examine your digestive system, including the stomach, pancreas, liver, kidneys, small and large intestines, soft tissue and blood flow in your belly.

During most of the exam, you will lie on your back with your arms at your sides.

For small bowel MRIs, you will need to lie on your stomach with your arms above your head. If that’s not possible for you (maybe due to an ostomy), you will lie on your back. If you are pregnant you will lie on your side during the exam.

Before the imaging part of the exam, you will be asked to drink about 1.5 litres of oral contrast liquid over 30 minutes. Check your appointment letter for any additional information.

You cannot eat or drink for four hours before your abdominal MRI, but you can have water to take any necessary medications.

The exam can take anywhere from 30 minutes to an hour.

Neurological MRI

Neurological MRIs examine your brain, spine, face, neck or central nervous system. You will lie on your back with your arms at your sides during the MRI. You will wear a special mask that covers your head and face, kind of like a hockey mask. It has holes so you can see, and there is a mirror attached to the MRI machine so you can look down towards your feet. If you prefer, we can also cover your eyes with a hospital-provided facecloth.

If the MRI is for examining your eyes or optic nerves, we will lightly tape some gauze over your eyes to keep them closed during the exam to minimize movement.