Magnetic Resonance Imaging (MRI)
Magnetic resonance imaging (MRI) is a technique that produces highly detailed pictures of the human body. MRI uses powerful magnetic fields and radiofrequency waves to generate exceptionally well-defined images that are used to visualize internal body structures. The MRI scanner creates a powerful magnetic field and, through a series of complex processes, generates radio signals that are detected by a computer that converts them into images. The magnets and radio waves do not seem to have any harmful side effects.
MR imaging is better than a scan (computerized axial tomography) when evaluating soft tissues (e.g., fat, muscles). Although MRI is costlier and takes more time, picture quality is by far superior. Magnetic resonance imaging also enables us to see structures that cannot be adequately assessed with other imaging methods such as CT scans, ultrasound and standard radiography.
What is the purpose of this test?
Magnetic resonance imaging is primarily used to diagnose diseases. The images provide such tremendous detail that they can show the difference between normal and diseased tissue. This examination is frequently used to provide pictures of the brain, spinal cord, soft tissue, joints, back, abdomen and pelvis.
Preparation
- All hearing aids, jewellery (even body piercings), wallets with metal, keys, pencils, loose change, credit cards, pocket knives, hairpins and safety pins must be removed prior to the MRI scan. In short, any objects containing metal or metal fasteners must be removed.
- Wear clothing that does not have any metal fasteners.
Procedure
The MRI scanner looks like a large cylinder with a hole in the centre. The person lies on a table that slides into the middle of the hole. Although the apparatus makes noise as it scans, it is not painful. It is very important to remain completely still for the duration of the examination which can last between 20 and 60 minutes.
Contraindications
Persons with metal implants (e.g., pacemakers, defibrillators, etc.) cannot undergo MRI scans. Particular attention, however, must be given to patch medication. Unless it is certain that the patch does not contain conductive material, persons with transdermal patches must remove them before the MRI test.
What you should know before going for this test
When you go in for a blood test or any other medical exam, it's always a good idea to bring a complete list of any prescriptions, over-the-counter medications, or natural health products you're taking. Unless otherwise advised, it's best to take your medications as usual on blood test days. If in doubt, don't hesitate to talk to your healthcare professional.
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The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.