Introduced in the 1980s, MRI (magnetic resonance imaging) uses a strong magnet instead of x-rays to take pictures of the brain. It is one of the best and most precise mechanisms for examining the brain, so it is extremely common for doctors to use MRI for diagnosis in epilepsy. It allows them to look at nerve tissue, the flow of blood and spinal fluid, and any tumors or other localized changes or injuries.

We spent a day with Dr. Manzar Ashtari and Dr. Elizabeth Lustrin at the Long Island Jewish Medical Center so that we could go step-by-step through the procedure with you.

When you arrive, you will meet with a technician, who will explain the test. Here, the technician is showing the apparatus that is used to keep the head still for brain MRI. The technician will also ask whether you are wearing any metal or have any metal in your body (such as a pacemaker, plate, or clips). Because the machine uses a very strong magnet to create the images, metallic items can be dangerous or can interfere with the scan. Avoid wearing zippers, jewelry, or hearing aids when you go for an MRI scan. The technician brings you to the self-contained room where the MRI machine is located, and helps you lie down on the table. To make you comfortable, you may be given a blanket and padding to place under your knees. The machine will make some loud sounds while it adjusts and takes the pictures, so you will be given earplugs similar to these. Many centers now offer music, or even movies to watch. The technician positions your head into the apparatus. It is extremely important to remain still during the test, as movement can blur the pictures. When the machine (called a scanner) is turned on, you will be moved slowly into the tunnel. It is a confined space, so many people become frightened. The technician will give you an "emergency ball" with a button to push if you feel anxious. Then the technician will leave the room. While the pictures of your brain are being taken, the technicians sit together outside the room and watch as the pictures are processed. The entire test lasts from 30 minutes to 1 hour. The MRI scanner takes many pictures of your brain. The pictures are then reformatted in the computer, so the doctor can view many different thin "slices" of your brain from several different angles. This view (from the side) is called a sagittal view. As each image comes up, the technicians look closely for any abnormalities. They can adjust the contrast or angle of the pictures according to what appears. When you are finished, the pictures are packaged together for review, and you may go home. Doctors will review and interpret your entire MRI study later. Typically, your doctor will receive the results within several days to a week.

Reviewed and revised March 2004 by Ruben Kuzniecky, MD, epilepsy.com Editorial Board.