Main menu


When does a doctor order an MRI of the head?

 Magnetic resonance imaging (MRI) of the head is a test that produces detailed images of the brain and brainstem. An MRI machine creates images using a magnetic field and radio waves.

An MRI scan differs from a CT scan or X-ray in that it does not use radiation. 

An MRI scan combines images to create a 3-D image of internal structures, so it's more effective than other scans at detecting abnormalities in small brain structures such as the pituitary gland and brainstem. 

Sometimes, a dye may be given, through an intravenous (IV) line, to better visualize certain structures or abnormalities.

Why do you need a head MRI?

Head MRI is a useful tool for detecting several brain conditions, including:

  • An aneurysm, or bulge in a blood vessel in the brain.
  • Multiple Sclerosis.
  • Spinal cord injuries.
  • Hydrocephalus is an accumulation of spinal fluid in the cavities of the brain.
  • brain attack.
  • infections.
  • neoplasms;
  • cysts;
  • swelling;
  • Hormonal disorders, such as acromegaly and Cushing's syndrome.
  • bleeding;
  • Vascular problems.
  • A problem due to a previous head injury.

A head MRI can also help determine if you've suffered any damage from a stroke or head injury. 

The doctor may also order a head MRI to investigate symptoms such as:

  • dizziness;
  • Weakness.
  • seizures;
  • Changes in thinking or behavior.

Chronic headache.

These symptoms may be due to a problem with the brain, which an examination can help detect.


Functional magnetic resonance imaging (fMRI) of the brain is useful for people who may be having brain surgery. It can also identify the areas of the brain responsible for speech, language, and body movement. 

It does this by measuring the metabolic changes that occur in your brain when you perform certain tasks. During this test, you may need to perform small tasks, such as answering basic questions or tapping with your fingertips.

In addition, there is a type of MRI called magnetic resonance angiography (MRA), which better examines the blood vessels in the brain.

How do you prepare?

Your doctor needs to know if you have any metal in your body, including:

  • Inner ear transplant.
  • artificial joints.
  • pacemaker;
  • Certain types of heart valves.
  • Vascular stents.

He or she will also ask if you have ever worked with sheet metal or had metal splinters. 

All of these things can affect your safety is undergoing an MRI. In the case of defibrillators, these items can stop working properly due to the strong magnetic field of the MRI.

And if you're wearing anything that contains metal, including jewelry or sunglasses, you'll need to remove those items. 

Dental braces and fillings usually aren't a problem, but pocket knives, pens, staples, and some dental appliances can interfere. 

You should also tell your doctor if you are pregnant. The magnetic field of an MRI affects fetuses in a way that is not yet fully understood.

If you have a phobia of enclosed spaces, you may need to take sedatives during the exam or have an open MRI. 

Open MRI machines have wider tunnels, which tend to be more tolerable for patients with claustrophobia.

What happens after an MRI of the head?

After the test, you can get dressed and leave the test site. But if you are sedated for the exam, staff may move you to a recovery area until you wake up from the sedative.

The radiologist will analyze the MRI images and provide the doctor with the results. Your results will be available quickly if the head MRI is an emergency procedure.

The next steps will depend on whether the results reveal anything unusual or the doctor discovers the cause of any abnormalities.