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Magnetic Resonance Imaging (MRI) of the Head

Risks continued...

An MRI can cause a burn with some medicine patches. Be sure to tell your doctor if you are wearing a patch.

There is a small chance of an allergic reaction if contrast material is used during the MRI. But most reactions are mild and can be treated with medicine. Contrast material that contains gadolinium may cause a serious problem (called nephrogenic systemic fibrosis) in people with kidney failure. If you have decreased kidney function or serious kidney disease, tell your doctor before having an MRI scan.

There also is a slight risk of an infection at the IV site if contrast material was used.

Results

Magnetic resonance imaging (MRI) is a test that uses a magnetic field and pulses of radio wave energy to take pictures of the head.

The radiologist may tell you some of the results of the MRI right after the test. Full results are sent to your doctor or specialist in 1 to 2 days.

Magnetic resonance imaging (MRI) of the head

Normal:

All structures of the head—the brain, its vessels, spaces, nerves, and surrounding structures—are normal.

No abnormal growths, such as tumors, in or around the brain are present.

No bleeding, abnormal blood vessels (AV malformations), abnormal pockets of fluid, blockage in the flow of blood, or bulges in the blood vessels (aneurysm) are present.

No signs of infection or inflammatory disease, such as encephalitis or meningitis, are present.

Abnormal:

Tumors in the brain or in areas outside the brain, such as an acoustic neuroma, are present.

Bleeding or swelling (edema) in or around the brain is present.

Areas of infection or inflammatory disease, such as encephalitis or meningitis, are present.

Abnormal areas in the brain may mean that certain diseases, such as Huntington's disease, multiple sclerosis, Parkinson's disease, or Alzheimer's disease, are present.

Bulges or weak areas (aneurysms) or abnormal blood vessels (such as an AV malformation) are present.

What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include:

  • Being pregnant. An MRI test is not usually done during pregnancy even though the strong magnetic field is not known to be harmful.
  • Having medical devices with metal. The MRI magnet may cause these devices to not work right or to have problems during an MRI scan. This test may not be done if you have:
  • Being unable to lie still during the test.

WebMD Medical Reference from Healthwise

Last Updated: November 29, 2012
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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