Magnetoencephalography (MEG) scan is the newest technique used to precisely map functional areas of the brain. Unlike magnetic resonance imaging (MRI) pictures of the brain, the MEG scanner generates a real-time movie of brain activity as a patient is asked to do specific exercises.
Currently the best method for generating preoperative brain maps, the scan helps neurosurgeons determine the best surgical approach. Because a MEG scan pinpoints the affected area of the brain, the total amount of brain tissue removed during surgery is limited and very accurate.
This test requires no injections and is an entirely painless procedure for both children and adults. A MEG scan must be ordered by a physician. The MEG Center at Nebraska Medicine is a nationwide leader in clinical MEG mapping.
The MEG scanner is most commonly used for:
- Identifying and localizing epileptic tissue
- Functional brain mapping prior to tumor resection
- Functional brain mapping before epileptic tissue removal
- Functional brain mapping prior to arteriovenous malformation surgery
The MEG scanner works by measuring and recording the brain’s magnetic fields that are created by the brain’s electrical activity. The scanner detects instantaneous changes in brain activity, allowing doctors to track changes that happen in milliseconds.
- The MEG Room
- MEG recordings are done in a special shielded room (which looks like a bank vault) that blocks magnetic fields in the environment. This ensures that only the magnetic fields generated by the brain are detected by the MEG sensors. It is necessary to remove all metal and jewelry before a MEG scan and patients may not use hairspray or makeup (which may contain traces of metal) that may interfere with the scan.
- The Helmet
- A person sits inside a device which resembles a helmet made of 306 super-cooled sensors that measure changing patterns of the brain’s magnetic activity. During the scan, the patient may be asked to perform a specific task such as tapping a finger or looking at pictures.
- The Scan
- A MEG scan of a patient reveals the person’s brain centers for language, movement (motor), touch sensation (somatosensory), vision and audition (sound). This picture shows the location of individual body parts in red and a brain tumor in green. To map a patient’s language function, the MEG scientist or physician would engage the patient in reading. The MEG scanner quietly and non-invasively detects the parts of the brain which are being used to read. When mapping a motor function of the right arm, the patient may be asked to repeatedly wiggle their arm.
- The Result: A Detailed Map of the Brain
- After the MEG scan, the MEG recordings are combined with a magnetic resonance imaging (MRI) scan, which shows the actual structure of the brain. The combined scan, called magnetic source imaging (MSI), shows areas of the brain that may be generating seizures as well as the areas of normal brain function with precise timing. MSI can provide neurosurgeons a detailed map that allows them to remove only damaged brain tissue while preserving healthy tissue.
- National Association of Epilepsy Centers – Level Four distinction
- American Clinical Magnetoencephalography Society (ACMEGS)
- International Society for the Advancement of Clinical Magnetoencephalography (ISACM)
As an academic medical center and teaching hospital for the University of Nebraska Medical center, one key focus is offering world-renowned neurological science services. The MEG scanner allows us to conduct research and further physicians’ knowledge which will ultimately benefit the patients throughout the region.
The MEG Center at Nebraska Medicine is located in Clarkson Doctors Building South, Room 222 near the intersection of 44th and Farnam streets.
MEG Center Staff
- Deepak Madhavan, MD, medical director
- Tony Wilson, PhD, scientific director
- Nichole Knott, REEGT, technician
MEG Scans are performed by physician request, generally as a pre-surgical diagnostic test. To schedule an appointment with an epilepsy specialist or neurosurgeon at Nebraska Medicine, please call 800-922-0000 or visit the Find a Physician link.
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