Because MRI does not involve the use of x-rays, it is safe for the majority of people.
Certain people, however, may be unable to undergo the procedure. These include:
Those who have implanted medical devices, including heart pacemakers and inner ear implants
Those with metal close to or in an important organ, for example a piece of metal in the eye possibly from an old injury, or metal clips in the brain following treatment for a brain aneurysm
The reason for these limitations is that the powerful magnetic field of the scanner may interfere with the internal mechanism of some of these medical devices, which may be dangerous, as well as the fact that the presence of metal will cause poor quality pictures if it is near the part being scanned.
While there are no known hazards, MRI is not proven to be safe during pregnancy.
What Are The Risks Of An MRI
Because MRI uses low-energy, non-ionizing radio waves, there are no known risks or side effects. In fact, since the technique uses no radiation, it can be repeated with no known adverse effects.
While there are no known hazards, MRI is not proven to be safe during pregnancy. If a pregnant woman must undergo an MRI, she will be asked to sign a special consent form.
The magnet at the center of the procedure may affect, or be affected by, any person fitted with a pacemaker, hearing aid, or other electrical device. People with such devices should advise the physician or technician. They are generally advised not to have an MRI.