Health Topics for Tests and Exams

Respiratory Care

Cellular Immunology Diagnostic Lab

MRI (Magnetic Resonance Imaging)

MRI stands for magnetic resonance imaging. The procedure uses a strong magnetic field and a radio beam to create a picture of the internal organs. MRI provides better views of body tissues than x-ray and CT scans. Bone does not block MRI. It can make pictures from angles that are difficult with CT scans and can produce images of organs in motion. MRI avoids the health risks related to x-ray exposure or contrast dyes used for x-ray tests. It causes no known harm to cells.

MRI is expensive and is usually reserved for cases when other imaging methods are not sufficient. It is used to evaluate:

• brain tumors, infections, and excess fluid

• spinal cord disorders

• nerve disorders, such as multiple sclerosis

• problems with joints

• bony and soft tissue tumors

• diseases of blood vessels

• irritation and infection in bones or other tissues and

• problems with the adrenal glands, kidneys, prostate, and bladder

The test cannot be given to pregnant women or people with pacemakers. No metal other than tooth fillings is allowed on the body during the MRI. The test takes up to 90 minutes. While the person may stay dressed, all metal objects must be removed. This includes jewelry, hearing aids, glasses, dentures, belts, and bras with wire in them.

The person lies on a bed that slides into a small tunnel. A mild sedative may be given to people who fear enclosed spaces. The patient must remain still during the scan. The scanner makes a lot of loud clicking and whirring noises. On occasion, examiners must inject a dye containing very small amounts of a radioactive substance. Radiation exposure from the dye is extremely low and is safe.

Normal activity may be resumed after the test.

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