MRI
MRI (magnetic resonance imaging) is a diagnostic procedure that combines a powerful magnet, radio waves and computer technology to provide detailed images of tissues, muscles, nerves and bones. Because MRI uses magnetic force and radio waves to create images, there is no radiation exposure during the procedure. MRI is often used instead of CT to study soft tissues or organs because bones do not obscure the organs and soft tissues as they do with CT imaging.
MRI can be used to assess everything from ruptured discs in the spine to detecting brain tumors and vascular diseases through techniques such as:
- Breast MRI can be a more effective imaging technique than mammography for some women, and can provide additional details for diagnosing and evaluating breast abnormalities.
- Angiography (MRA) evaluates blood flow, or detects brain aneurysms or blood vessel abnormalities. It is used to visualize renal, carotid and vertebral arteries, or examine the aorta for aneurysm.
- Perfusion and diffusion scanning examines blood flow through tissues to evaluate strokes.
What to Expect
MRI units have a large cylinder shape with an opening on each end. You will lie on a cushioned table that moves into and out of the cylinder. You will not feel anything as the exam is performed, but you will hear the unit give off a humming, thumping, clicking and knocking noise as your images are created. Your technologist is in constant visual contact and verbal communication with you throughout the examination.
Examination times vary based on the exam ordered. You may also require IV contrast with your examination. While this contrast is not the same contrast used for CT scans, blood tests may be required to check for normal kidney function.
If you have a pacemaker, cochlear implants, aneurysm clips or are pregnant, you may not be a candidate for an MRI procedure. Communicate these conditions to your physician prior to being scheduled for this procedure. Please communicate with your physician prior to your appointment if you suffer from claustrophobia symptoms.
Be sure to report any metallic object in or on your body to the technologist before entering the MRI room.
On the day of your MRI, be conscious about how you dress, making a special effort to minimize accessories containing metal such as belts, jewelry, metallic buttons, etc.