What Type of Brain Imaging is Warranted for This Headache?

When a patient has a dangerous headache, healthcare providers will order imaging of the brain. This imaging will reveal whether there is a serious condition going on inside or around the brain, like a bleed.

But what type of imaging will your healthcare provider order? A CT scan or an MRI? Or a magnetic resonance angiography (MRA) of the brain, which is essentially an MRI of the brain's blood vessels.

The American College of Radiology has specific recommendations to help determine the optimal type of brain imaging needed for an acute headache. These recommendations may help you better understand why your healthcare provider is ordering one test over another.

Headache in a Person Who is Immunocompromised

The state of being immunocompromised means that a person has an impaired immune system, weakening their ability to defend themselves against infection. Their impaired immune system could be secondary to a number of factors, like disease (e.g. diabetes, HIV) or drugs (e.g. steroids, chemotherapy).

Imaging: In this case, an MRI of the head with and without contrast media is recommended.

Headache in People Older than 60 with Suspected Giant Cell Arteritis

Giant cell arteritis (GCA) is a type of vasculitis (inflammation of blood vessels) that typically causes a headache in the temple area and may be accompanied by a number of other symptoms including fatigue, jaw pain, and body aches. The most worrisome feature of GCA is vision loss.

Imaging: In this case, an MRI of the head with and without contrast media, as well as an MRA or CTA of the head and neck can be helpful. However, a biopsy of the temporal artery is often required to make the diagnosis with certainty.

Headache With Suspected Meningitis

Meningitis is an infection of the membranes that surround the brain and spinal cord. It is most commonly caused by a bacteria or virus, and rarely a fungus. Brain imaging is performed when a person with suspected meningitis is at a high risk for brain herniation—but ultimately a lumbar puncture is performed to make the diagnosis of meningitis. 

Imaging: In this case, a CT or MRI of the head without contrast media is recommended. 

Severe Headache in Pregnancy

While most headaches in pregnancy are benign, a healthcare provider may order brain imaging if the headache is severe or associated with other worrisome symptoms, like neurological symptoms. 

Imaging: In this case, a CT or MRI of the head without contrast media is recommended. 

Severe, One-Sided Headache Caused By Possible Arterial Dissection 

Dissection refers to the tearing of the inside wall of the blood vessels that supply the brain. Dissection of the carotid and vertebral arteries usually causes pain of the head and/or neck and is a life-threatening condition, as it can lead to stroke.

Imaging: In this case, MRI of the head with and without contrast media, MRA of the head and neck, or CTA of the head and neck is recommended.

Sudden Onset or Severe Headache

A headache that is severe and/or begins suddenly is particularly worrisome for a bleed in the brain (i.e. subarachnoid hemorrhage) and warrants emergent brain imaging.

Imaging: In this case, a CT of the head without contrast media, CTA of the head with contrast media, MRA of the head with or without contrast media, or MRI of the head without contrast media is recommended.

A Word from Verywell

If you see your healthcare provider or go to the emergency room with a potentially dangerous headache, imaging of the brain will be ordered. While your healthcare provider will know which imaging to request, it's reassuring to know there are recommendations your practitioner is following and what you can expect.