MRI is magnetic resonance imaging, a special test that produces very clear and detailed pictures of the organs and structures in the body. It uses a powerful magnetic field, radio waves, and a computer to create cross-sectional images. It is superior to X-ray and CT scan, which only pick up the bony and radio-opaque tissues. In MRI, even the soft tissue structures like ligaments, cartilages and organs such as eyes, brain, heart, etc are clearly seen.
When is it used?
It is useful for injuries especially those involving the shoulder, back, or neck. The abnormalities in the brain, spinal cord are also clearly seen. The size and location of tumours can also be made out. An accurate diagnosis can be made on the basis of which specific treatment is begun.
What preparation is needed?
No special preparation is needed. Wear loose, comfortable clothing without metal fasteners like zips or clasps as metal interferes with the test. Avoid wearing jewellery. Inform the doctor of any surgical implants made of metal. A pacemaker or metal fragments inside the eye are contra-indications for an MRI.
What happens during the procedure?
The patient lies down on a stretcher that moves into the MRI machine and has to keep very still during the procedure for the pictures to be clear. In some cases, a dye may be injected to increase the contrast. Generally it takes half to one hour for the procedure. Earplugs and or music are provided to mask the noise of the machine. The patient goes home after the procedure.
What are the benefits and risks?
MRI examination is a painless, out-patient diagnostic procedure with no radiation and there are no harmful side effects. Take care to avoid wearing any metallic things as they can interfere with the test. Some people who are scared of small, enclosed spaces may feel claustrophobic.