MRIs for Headache and Migraine Diagnosis

Medically Reviewed by Jennifer Robinson, MD on January 27, 2022
Written by WebMD Editorial Contributors
4 min read

An MRI is a test that makes clear images of the brain without the use of X-rays. Instead, it uses a large magnet, radio waves, and a computer to produce these pictures.

The scan can give doctors information about the structure of the brain and brain chemicals to help them find the cause of your headaches.

Your doctor might recommend one if you're getting headaches daily or almost every day. You might also get one if you had a CT scan that didn’t show clear-cut results. An MRI may also be ordered if there is a change in your headaches or anything unusual about them, if there are additional symptoms happening with your headaches, or if there is concern there might be a structural problem causing your headaches.

MRI scans also can look at parts of the brain that aren't as easily viewed with CT scans, such as the spine at the level of the neck and the back portion of the brain. An MRI can’t diagnose migraines, cluster, or tension headaches, but it can help doctors rule out other medical conditions that may cause your symptoms, such as:

Yes. The MRI exam poses no risk to the average person.

The scan is also safe for people who've had heart surgery and people who have these medical devices:

  • Surgical clips or sutures
  • Artificial joints
  • Staples
  • Cardiac valve replacements (except the Starr-Edwards metallic ball/cage)
  • Disconnected medication pumps
  • Vena cava filters
  • Brain shunt tubes for hydrocephalus

Some things may mean you shouldn’t have an MRI or may raise concerns about you getting this test. Tell your doctor if you:

  • Have a heart pacemaker
  • A cerebral aneurysm clip (metal clip on a blood vessel in your brain. The newer aneurysm clips are safe, meaning you can get an MRI with them. But if they were put in a long time ago, your doctor needs to have information about them to determine if they are safe.)
  • Are pregnant. You can usually get an MRI if you are pregnant, but you cannot have one with contrast.
  • Have an implanted insulin pump (for treatment of diabetes), narcotics pump (for pain medication), or implanted nerve stimulators
  • "TENS" device for back pain
  • Metal in your eye or eye socket
  • Cochlear (ear) implant for hearing problems
  • Implanted spine stabilization rods
  • Severe lung disease (such as tracheomalacia or bronchopulmonary dysplasia)
  • Gastroesophageal reflux (GERD)
  • Weigh more than 300 pounds. Your weight doesn't prevent you from getting this test, but it may make it difficult for you to lay completely flat.
  • Have trouble lying on your back for 30 to 60 minutes
  • Claustrophobia (fear of closed or narrow spaces). You can still get an MRI, but you may need sedation, meaning medication to help you relax.
  • Set aside about 2 hours for the test. In most cases, it takes 40 to 80 minutes, during which technicians will get several dozen images of your brain.
  • Leave personal items such as a watch, wallet, including any credit cards with magnetic strips (they will be erased by the magnet), and jewelry at home if possible, or take them off before the scan.

Sometimes, you’ll get a drug to make you feel relaxed and drowsy. You may also need to change into a hospital gown. Also, MRI machines can be loud, so if you’re sensitive to noise, ask for earplugs before the scan starts.

  • As it begins, you'll hear the equipment making a muffled thumping sound that will last for several minutes. Other than the sound, you shouldn’t feel anything unusual during the scanning.
  • For some MRI exams, you'll need a shot of a "contrast material" into your vein. It helps doctors see certain structures in your brain on the scan images.
  • Feel free to ask questions. Tell the person giving you the test or the doctor if you have any concerns.

Generally, you can go back to your usual activities and normal diet right after a MRI test.