Clinical Services – For Patients

The Biomagnetic Imaging Lab offers two types of noninvasive brain imaging exams – MEG and MSI.

A MEG exam uses magnetoencephalography (MEG) to records magnetic fields emitted by brain cells (neurons) through a silent MEG scanner that fits on your head like a helmet.

An MSI (magnetic source imaging) exam combines MEG and MRI test results to create a functional map of brain activity that can identify areas of normal and abnormal brain activity and areas of function, including language, hearing, touch, and movement.  MEG + MRI = MSI. Clinically, MSI provides increased localization of spike activity in patients with seizures and a deeper look at brain activity than EEG alone. MSI is typically used by physicians to enhance clinical diagnosis, surgical planning, and intra–operative navigation.

Before Your MEG Exam

• Let us know about any implants in your body. This test is very sensitive to metal and the radiology technologist will review prior to scheduling. Do any of the following conditions apply to you?
  • Implanted electrical device such as a pacemaker, vagus nerve stimulator (VNS), or deep brain stimulator (DBS).
  • Implanted metal device or prosthesis, such as a metal plate, aneurysm clip, rod, pin, screw, etc.
  • Non-removable dental work, such as braces, permanent retainer, bridge, etc.
• Wear clothes free of metal zippers or snaps above the waist (pants with zippers are ok).
• Avoid makeup, especially eye make-up, which can contain metallic ingredients that can affect the scan.
• Wear your hair down and free of hair products.
• Let us know if we can arrange interpreting services for you.
• Bring a list of your current medications.

Before Your MSI Exam

• ​Before your MSI exam, eat normally and take daily medications as usual, unless instructed otherwise by your physician.
• Remove all metallic items from your body, such as belts, eyeglasses, cell phones, credit cards, keys, etc.
• If you have metal on your clothing, you will be asked to change into a hospital gown.
• A radiology technologist will verify your identification and record a brief interim history including your current symptoms.
• If you are having an EEG exam done at the same time, we will place electrodes on your scalp with a little electrode paste prior to your exam.

During Your MSI Exam

• You will be asked to lie on a bed and the technologist will place you in the scanner. The scanner fits on your head like a helmet and is open.
• You will be asked to remain still while the scan is running. Usually, each scan lasts about 4 to 10 minutes, and in between the scans you will be able stretch and readjust your position. Most appointments involve multiple scans and last between 1-2 hours but can be longer or shorter depending on what your doctor has ordered.
• At times you will be asked to relax with your eyes closed and other times you may be asked to actively participate in the scan by listening to tones or responding to pictures.
• There is a two-way intercom and video monitoring system in the room so the technologist can monitor and communicate with you.

After Your MSI Exam

• The technologist will remove the electrodes if you had an EEG performed and escort you out of the room.
• The clinical team will analyze and review your scan results and send the results to your health care professionals.

For Pediatric Patients

Children are welcome to bring a favorite stuffed animal for the exam, as long as it does not contain any metal.

If you have any additional questions about your appointment, please contact the Biomagnetic Imaging Lab at (415) 476-6888.