Functional Magnetic Resonance Imaging (fMRI)

Functional MRI (fMRI) is a type of MRI exam that looks at activity in areas of the brain. You will be asked to perform certain tasks while you are inside an MRI scanner. The areas of the brain that are working the hardest will appear brighter on the image that is being recorded.

MRI uses a large magnet, radio waves, and a computer to produce detailed images of the body. An MRI system includes a scanner shaped like a donut and a motorized table that slides in and out of the opening. MRI does not use radiation.

How is fMRI used?

fMRI is most commonly used to plan brain surgery and procedures that involve the brain. It shows doctors what parts of the brain control certain actions and abilities so that they can avoid disturbing those areas.

Is it safe for me to have fMRI?

For most people, fMRI is safe. You will be asked detailed questions about any devices, implants, or other metal objects you may have in or on your body.  As long as your device or implant is certified as MRI safe, you may have fMRI. If there is not enough information or your device is determined to be unsafe, your doctor will schedule a different type of test.

How do I prepare for the test?

• Avoid anything that contains caffeine on the day of your procedure.
• Continue to take your medications unless instructed not to.
• Talk to your doctor if you need medication for anxiety or to help you relax.
• Wear comfortable clothes to your appointment.
• Do not wear jewelry or makeup.

On the day of the test

• Check in for your appointment on the Connect patient portal. You may also check in when you arrive at the imaging center.
• Remove all metal objects, including jewelry, hair accessories, phones, wallets, and keys. We will give you a locker to secure them.
• We will review your medical history and MRI Safety Checklist with you.
• Some fMRI exams require contrast, or dye, to help highlight certain parts of the brain. If you are having fMRI with contrast, a nurse will insert an intravenous line (IV), usually in your arm. The contrast (gadolinium)will be administered during the exam.
• Prior to the examination a neuroradiologist will review the instructions with you. It is very important that these instructions are followed exactly for an accurate exam.
• A technologist will ask you to lie on the MRI table. Your head will be placed inside a padded plastic helmet called a coil.  
• You will be offered a blanket and earplugs. You will also be given an emergency call button in case you need to urgently contact the technologist.
• The table will slide into the scanner, and a red light may shine on your body momentarily to position the area of interest in the center of the scanner.
• The technologist will leave the room but will be able to see, hear, and speak with you at all times.
• The scanner will make loud clicking, buzzing, banging sounds, and you may feel vibrations. This is normal and you should remain relaxed.
• During the scan, you will see images and the technologist will ask you to perform simple tasks based on the images you see. Examples of tasks include tapping your fingers when you see an image of a hand, or thinking of words that begin with a certain letter.
• The technologist will also record images of your brain at rest. It is important to lie still and relax so that we can record clear images.
• fMRI exams take about an hour. 

Are there any risks?

fMRI does not use ionizing radiation, the type of radiation used in X-rays and CT scans, and there are no known harmful side effects associated with temporary exposure to the magnetic field used by MRI scanners. There is a slight risk that you will develop an allergic reaction to the contrast agent (gadolinium).

After the test

After the exam you can immediately resume your normal activities. If you were given contrast, drink six to eight eight-ounce glasses of water in the 24 hours after the MRI to help remove the gadolinium dye from your body. A radiologist who specializes in imaging of the brain will analyze the fMRI images and share the results with the doctor who requested the exam. Your doctor will then discuss the results with you.