Brain & Nervous System Health Center
Magnetic Resonance Imaging (MRI) of the Head
Magnetic resonance imaging (MRI) is a test that uses a magnetic field and pulses of radio wave energy to take pictures of the head. In many cases, MRI gives information that cannot be seen on an X-ray, ultrasound, or computed tomography (CT) scan.
For an MRI
of the head, you lie with your head inside a special machine (scanner) that has
a strong magnet. The MRI can show tissue damage or disease, such as infection,
inflammation, or a tumor. Information from an MRI can be saved and stored on a
computer for more study. Photographs or films of certain views can also be
made. See MRI images of a person who has had a
stroke 
or a
seizure .
In some cases, a dye (contrast material) may be used during the MRI to show pictures of structures more clearly. The dye may help show blood flow, look for some types of tumors, and show areas of inflammation.
MRI of the head may be used to look for the cause of headaches. For more information, see:
See pictures of
a standard MRI machine and an
open MRI machine .
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Headaches: Should I Have Imaging Tests to Find Out What's Causing My Headaches?Why It Is Done
Magnetic resonance imaging (MRI) of the head is done to:
- Look for the cause of headaches.
- Help diagnose a stroke or blood vessel problems in the head. Problems with blood vessels may include an aneurysm or abnormal twisted blood vessels that are present at birth (this is called an arteriovenous [AV] malformation).
- Check blood flow or blood clots to the brain. MRI can show bleeding in or around the brain.
- Check symptoms of a known or suspected head injury.
- Check symptoms such as change
in consciousness, confusion, or abnormal movements. These symptoms may be
caused by brain diseases, such as
Huntington's disease,
multiple sclerosis (MS),
Parkinson's disease, or
Alzheimer's disease. See an
MRI showing MS in the brain .
- Check for "water on the brain" (hydrocephaly).
- Look for tumors, infections, an abscess, or conditions of the brain or brain stem, such as encephalitis or meningitis.
- Check the eyes, the nerves from the eyes to the brain (optic nerves), the ears, and the nerves from the ears to the brain (auditory nerves).
- Look for problems of the pituitary gland.
- Investigate or follow a finding seen on another test.
WebMD Medical Reference from Healthwise
