Many brain imaging techniques are used today, each one visualizing your brain in a unique way.

Brain scan on digital tabletShare on Pinterest
Nikada/Getty Images

If your doctor has recently ordered a brain imaging scan, you might wonder what your upcoming session will be like or what types of brain imaging techniques might be used.

Experts have gradually improved techniques throughout the years to map out different parts of the brain and various brain functions.

There’s a lot that your doctor can learn from brain imaging, and the information that these scans provide can be helpful in forming a diagnosis and building a treatment plan.

While it may seem stressful to go in for brain imaging, you can take comfort in knowing that this is a safe and painless procedure.

The year 1924 marked the first human electroencephalography (EEG), recorded by German psychiatrist Hans Berger. This early EEG was able to detect electrical waves in the brain that would rise and fall as different brain cells communicated with each other.

Since then, neuroimaging techniques have gotten increasingly more sophisticated, and are an important tool for neurology and mental health specialists.

Commonly used brain imaging techniques are:

  • functional magnetic resonance imaging (fMRI)
  • computerized tomography (CT)
  • positron emission tomography (PET)
  • electroencephalography (EEG) and magnetoencephalography (MEG)
  • functional near-infrared spectroscopy (fNIRS)

One of the benefits of brain imaging is how easily it can be performed. It doesn’t require invasive steps and often simply involves laying down and being still while the scan takes place around you.

These modern brain imaging techniques enable doctors to map out the regions and functions of your brain in a non-invasive way.

Brain imaging has many roles in health care and makes the jobs of diagnosticians easier. Some uses of brain imaging techniques include:

  • identifying the effects of a stroke
  • locating cysts and tumors
  • finding swelling and bleeding

Doctors use a particular type of imaging method based on what they need to see in your brain. For example, if you are experiencing symptoms of multiple sclerosis (MS), your doctor can order an MRI scan to detect or rule out MS lesions. On the other hand, if you want to check for broken bones, they are more visible on a CT scan.

Brain imaging can also connect certain mental health issues to biological causes as well. According to a 2020 study, people with high levels of anxiety also displayed differences in brain connectivity when compared to people without anxiety. In addition, brain imaging can detect conditions such as early-stage psychosis.


Functional magnetic resonance imaging (fMRI) can detect changes in blood flow and oxygen levels that result from your brain’s activity. It uses the magnetic field of the scanner to affect the magnetic nuclei of hydrogen atoms, so they can be measured and converted into images.

MRIs display anatomic structure and fMRIs measure metabolic function.

fMRIs have many uses, such as:

  • assessing brain activity
  • finding brain abnormalities
  • creating pre-surgical brain maps


A computerized tomography (CT) scan is a series of X-ray images converted into cross-sectional images of your brain. These X-rays are combined to form cross-sectional slices or even a 3-D model of your brain. The results of a CT scan can also provide more detail than a standard X-ray.

CT scans can:

  • find certain types of brain injuries
  • identify cancer
  • locate brain swelling or bleeding
  • reveal structural brain changes from schizophrenia


A positron emission tomography (PET) scan uses a radioactive tracer that attaches to the glucose in your bloodstream. Since your brain uses glucose as its primary fuel source, the tracer accumulates in areas of higher brain activity.

A PET scan is able to see these tracers and observe how they move and accumulate in your brain. This allows doctors to see trouble spots where glucose isn’t moving correctly.

PET scans can evaluate:

  • seizures
  • Alzheimer’s
  • tumors


An electroencephalography (EEG) test measures your brain waves. Before the scan, clinicians will attach small electrodes to your scalp that are attached to wires. These electrodes detect electrical activity in your brain and send it to a computer where it creates a graph-like image. Each type of frequency appears on its own line and gives your doctor information about your brain activity.

EEG can detect issues such as:

  • anxiety
  • head injuries
  • epilepsy
  • sleep disruption


Magnetoencephalography (MEG) measures the magnetic field from neuron electrical activity. This type of scan can locate and identify malfunctioning neurons in your brain. Doctors use MEG to evaluate both spontaneous brain activity, as well as neuronal responses triggered by stimuli.

MEG allows doctors to assess areas such as:

  • epilepsy sources
  • motor areas
  • sensory areas
  • language and vision


Near-infrared spectroscopy (NIRS) monitors your brain’s oxygen saturation. It uses infrared light to detect variations in hemoglobin oxygen levels in your blood. Since oxygen is critical for your brain to function properly, NIRS can assist doctors in any clinical setting where brain oxygen levels may fluctuate.

NIRS is used to monitor:

  • brain oxygen levels during cardiac surgery
  • brain function and oxygenation levels in preterm infants in a neonatal intensive care unit (NICU) setting

Brain imaging methods offer medical professionals a view of your brain to see if it’s structurally and functionally typical. There are several different brain scan types that map out different parts of your brain, but your specialist will know which one to use for the issue they’re investigating.

Brain imaging techniques do more than simply find medical issues, though. They can also identify brain differences associated with certain mental health conditions, such as schizophrenia, early-stage psychosis, and anxiety disorders.

If your doctor is sending you in for brain imaging, remember that this is a non-invasive procedure that will help your doctor have a clearer understanding of how your brain is functioning. After they receive the results, they can create the best and most accurate treatment plan specific to your needs.