MRI Safety Information

Magnetic resonance imaging, or MRI, is a test used to diagnose disease or identify abnormalities in a patient's body. With MRI, doctors are able to distinguish between healthy and unhealthy tissues, according to RadiologyInfo. MRI is used to assess various regions of the body, including the brain, spine, joints, blood vessels and heart. Like all medical procedures, MRI has health and safety risks along with benefits.

History

• The development of MRI stretched over the course of several decades. In 1946, two scientists, Edward Purcell and Felix Bloch, discovered magnetic resonance. Because MRI required advanced technologies, it was not until 1977 that the first MRI scan took place. Before 1977, MRI was used in chemical and physical research rather than in medicine.

How It Works

• MRI uses magnets, radio waves and a computer to produce images, in contrast with the radiation used for x-rays, for example. Sometimes contrast material (gadolinium) is used to produce better images. The unit consists of a table, on which the patient lies, and a round tunnel-shaped scanner. Inside the scanner is a magnetic field that causes the atomic particles in the patient's tissues to line up a certain way. The radio waves react with these particles to form signals that get converted into images. Healthy and unhealthy tissues produce discrete signals and, thus, different images.

Main Safety Issue: Interference

• MRI is considered safer than some other tests because it does not expose the patient to radiation. There is, however, one significant worry: the interference of the magnetic field with anything made of iron, including aneurysm clips, implants, jewelry, electronic devices and pacemakers. (See RadiologyInfo's safety guide for a complete listing.)

  The interaction between the magnetic field and metal objects may cause complications that range from life-threatening to distortion of images. RadiologyInfo says that because of the seriousness of these risks, certain people, such as pacemaker wearers, cannot have MRI tests.

Other Safety Concerns

• Other safety risks include rare allergic reactions to the contrast material, feeling frightened in the case of those who suffer from anxiety and claustrophobia, and possible dangers to fetal development in pregnant women. MRI is safer to use in pregnant women than other procedures, according to RadiologyInfo.

Preparation for MRI

• To ensure that the MRI is carried out safely, you should prepare by informing your physician of your medical history, allergies and medications you are taking. You also need to complete a screening form that asks whether you are wearing anything that could interfere with the procedure. Fasting for several hours before the scan may be necessary.

  If you are breastfeeding, pump breast milk beforehand to avoid exposing your infant to contrast material through breast milk, as the material can stay in the body for up to 24 hours. If you have anxiety or claustrophobia, taking sedatives may help you cope with the discomfort of being in the restrictive environment of the scanner.

  Most important, remove metallic objects from your body to avoid magnetic interferences that might endanger your life or cause injury.