Overview Of MRI Safety:

In the United States there are over 10,000 MRI scanners and estimates are that 20,000,000 scans are performed in the U.S. annually! Unlike conventional X-ray and C.T. scanners, MRI obtains images by using high-strength magnetic fields and radio frequencies which are non-ionizing. As such, there is not the concern about radiation exposure that there is with some other imaging modalities.

MRI Safety has three integral components: Clinical, Operational and Facility Safety.

Clinical Safety:

While the magnetism from MRI scanners - which can be 60,000 times more powerful than the Earth's own magnetic field in some advanced clinical scanners - does not harm our bodies, the extreme magnetic force can act upon aneurism clips, shrapnel, pacemakers, and other types of medical implants. These interactions between high-strength magnetic fields and implants have caused injury, and even death.

Many newer medical devices can be scanned under specific conditions, but each device must be carefully checked against the manufacturer's specifications and independant test data. This information is available to your doctor and the MRI facility, but requires very specific information about the device and may not be advisable in all cases.

Operational Safety:

But even for patients with no shrapnel or implants in their bodies, MRI still has very unique risks. The size and strength of contemporary MRI magnets is such that they can attract very large, very heavy iron containing objects, and 'suck' them to the MRI. This, too, has caused serious injury and even death. Even smaller objects, bobby pins and nail clippers, have caused serious injury to MRI patients. And while the medical device manufacturers have made good progress in developing new implants which allow patients to be scanned reducing those risks, the proliferation and increasing strength of MRI magnets has contributed to an increase in these 'missile' accidents.

To protect against missile events, patients are required to remove all metal objects, sometimes changing into a hospital gown or scrubs. Patients may also be screened by a special type of metal detector which alarm only on magnetic materials such as iron and steel. Visitors and other personnel may be restricted from the areas near the magnet to help assure that no iron-containing materials are inadvertently brought into the MRI.

Facility Safety:

Every MRI facility should be designed to protect patient safety with features that include secured access to the magnet areas, provisions for medical gasses and 4-zone screening areas, and special metal detectors specifically designed to identify ferrous objects which can be threats near the MRI magnet. Other protections built-in to the imaging facility may not be readily apparent.

Most imaging facilities have extensive safeguards to protect patients against the risks associated with these high-strength magnetic fields and, even with these unusual risks, MRI is still one of the safest and most effective imaging technologies ever developed. Persons with concerns about MRI safety issues should talk with both their referring physician and the staff at the imaging facility. If you ever feel uncomfortable about the safety provisions at one MRI provider, find another provider who addresses your concerns. Do not skip a proscribed MRI scan.