Learn more about different types of imaging tests for migraine, common findings and some follow-up tips.
A severe migraine attack can be scary. When your head is throbbing for hours, you might start wondering if there is a serious problem. Fortunately, most migraine attacks are not dangerous—but, understandably, you want to know the cause of them.
While a brain scan may seem like the way to get answers, most of the time, these imaging tests are not needed to look for the cause of headache. For primary headache disorders like migraine, imaging is unable to identify the cause. Your doctor will likely diagnose migraine based on your symptoms, medical history and a physical and neurological examination.
However, your healthcare provider may recommend imaging in certain cases. These cases can include sudden changes in headache pattern or other concerning headache symptoms. Below, we explain the different types of imaging and when you might need one of these tests.
When would I need an MRI for migraine?
While many people with migraine don’t need an MRI, your doctor might recommend it if you have any headache red flags. These are sudden changes in headache patterns or certain signs that there may be a more serious underlying problem, including:
- Increase in frequency or changes in the intensity of headache
- Headache that changes when you move, like standing up from a sitting position, or when you lie flat
- New headache in a person over 50
- Headache that always occurs on the same side of the head
- Head pain that does not stop
- A sudden, extremely painful headache that comes on quickly
- Headaches that are brought on by coughing, straining, lifting heavy objects, bending over or during sexual activity
- Aura that lasts more than 1 hour
- Weakness on one side of the body or difficulty with walking, speaking, seeing or understanding
- Any headache that does not fit the typical pattern needed for a diagnosis
Contact your doctor right away if you have these symptoms; they can help determine if you need imaging. Depending on your case, you may be given an MRI or a CT scan.
What type of imaging is better for migraine? MRI or CT scans?
There are several types of imaging tests that can be used for headache and migraine: An MRI or a CT scan are the most commonly ordered.
A CT scan, or a CAT scan, uses X-rays to create images and show cross-sections of your body. The test typically takes only a few minutes. A CT scan is used in cases of urgent diagnoses, such as strokes, brain tumors or brain bleeding.
An MRI scan, on the other hand, uses a powerful magnetic field to take detailed pictures of the brain. MRIs can reveal various brain conditions, such as tumors, bleeding, inflammation, low spinal fluid pressure and blood vessel problems. An MRI takes longer than a CT scan, usually between 30 to 60 minutes, and it usually is more expensive. However, MRIs produce high-quality images and are better able to visualize the back portions of the brain.
You might hear the term “contrast” if your doctor discusses imaging with you. Both CT scans and MRIs can be done with or without contrast. Contrast is an injectable dye that allows your radiologist to see the structure of your brain in greater detail. Certain neurological conditions (like tumors or low spinal fluid pressure) may be easier to detect with contrast, so your doctor will recommend it in those cases.
What does migraine look like on an MRI?
It’s essential to remember that an MRI scan is not needed to diagnose primary headache disorders like migraine, tension headache or cluster headache. However, it can help doctors look more closely at your brain and rule out certain medical disorders that may mimic these headache disorders like brain tumors, spinal cord injuries and strokes.
In some migraine patients, an MRI may show white spots on the brain. These spots are called white matter hyperintensities (WMHs), which are lesions in the brain visualized by areas of increased brightness. They can vary in size and location in areas of the brain.
What are white spots on an MRI?
White spots on an MRI indicate that parts of the brain are inflamed and have had changes in water content. Although WMHs may look frightening, they do not mean anything is wrong with your brain. A review of migraine and changes in the brain from 2013 showed that these lesions are generally not linked to serious neurological or cognitive problems, and some researchers suggest that they do not affect brain health.
While studies show that people with migraine have an increased risk of brain lesions, WMHs cannot be used to diagnose migraine since not all people with migraine have these white spots. Also, WMHs are sometimes seen on MRIs of people without migraine symptoms.
The frequency of WMHs can increase simply because of normal aging. The older you become, the more likely these white spots can be seen on an MRI, regardless of whether or not you have migraine. Finding these white spots also allows doctors to check if there are other medical conditions, including multiple sclerosis, Lyme disease, heart disease, high blood pressure, diabetes, high cholesterol and strokes. This can help you get the proper treatment faster.
What if my results are normal, but I still get a headache?
It may be frustrating not to find out what’s causing your headache from imaging results, but this should not be surprising since the diagnosis of migraine is in part based on having normal imaging tests. Therefore, a normal MRI shouldn’t prevent your healthcare provider from diagnosing and treating your migraine. For example, they could work with you to identify migraine triggers, such as stress and weather changes, and suggest acute and preventive treatments to help you stop an attack quickly and decrease the frequency of future attacks.
If you continue having severe headaches that affect your life, it may be helpful to see a migraine or headache specialist.
Risks and Next Steps
MRIs are safe and have no risk of radiation exposure. However, it is understandable that some people may have hesitations about having these tests done.
In general, there are no known health hazards associated with getting an MRI. However, on rare occasions, contrast dye can trigger allergic reactions like nausea, headache and dizziness. An MRI also requires the person to lie still in a tube-shaped machine, which may be unpleasant for those with claustrophobia. Make sure to consult your physician before your test if you are sensitive to medications or have any concerns—they can help you feel more comfortable and supported throughout the process.
While these tests allow your doctor to assess brain structure and rule out other medical conditions, your provider will likely diagnose migraine through your medical history and a physical examination. By definition, primary headache disorders do not have a serious underlying cause, and having a normal MRI finding doesn’t make your migraine less valid.
Make sure to continue keeping track of your attacks and schedule an appointment with a headache specialist to help you set up a treatment plan.
The American Migraine Foundation is committed to improving the lives of those living with this debilitating disease. For more of the latest news and information on migraine, visit the AMF Resource Library. For help finding a healthcare provider, check out our Find a Doctor tool. Together, we are as relentless as migraine.
Reviewed for accuracy by the American Migraine Foundation’s subject matter experts, headache specialists and medical advisers with deep knowledge and training in headache medicine. Click here to read about our editorial board members.