What are the different types of brain scans?

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Jules Walters • First Published: Feb 18, 2023

One way to check that your brain is healthy is to have a brain scan. The human brain is probably the most complex object in the known universe, with 86 billion neurons or nerve cells. But is yours working as it should? One way to peek inside and find out is to have a brain scan.

There are four main kinds of brain scans to picture what’s going on inside our heads. It’s a painless procedure and worth looking into. I cover on this page the most commonly used types of scans available today.

Why would I need a brain scan?

A good question is why would a brain scan be worth the cost? Dr Daniel Amen, a psychiatrist and founder of the Amen Clinics brain-scanning company, asks what other medical speciality apart from psychiatry doesn’t actually look at the organ of interest?

Cardiologists scan our hearts, nephrologists look at our kidneys, but psychiatrists often prescribe medication based on symptoms without looking at an image of brain function.

Dr Amen is on a life-long mission to shine a light into the black box of our brains. Over the past 30 years, his clinics have built what he describes as the world’s biggest database of brain scans, using a brain imaging tool called SPECT (which stands for Single Photon Emission Tomography).

The four most commonly used brain scans

It may be that you’re just curious to see inside your brain, or you could be one of the millions of Americans experiencing brain fog, anxiety or depression.

So, these are the main kinds of brain scans currently available.

Single photon emission computed tomography (SPECT)

This is the kind of image Dr Daniel Amen’s clinics use. His clinics have scanned over 200,000 brains since 1991, from babies to centenarians.

SPECT brain scan imaging_showing 3D models of unhealthy & healthy brains

The imaging gives psychiatrists more information about their patients. However, you can also ask for an image as a healthy and curious consumer.

SPECT uses blood flow to show if there is good activity in the brain, too little or too much. It does this by using a radio-tracer, which is a small amount of a radioactive substance.

The most active part of the brain tends to be the cerebellum at the back of the skull, which controls muscle movement and memory.

A SPECT scan can help to look at what’s going in Alzheimer’s disease, damage through a traumatic brain injury (TBI), or drug abuse. It can also demonstrate the effects of chemotherapy, or the results of an inflammatory infection such as lyme disease.

As Dr Amen says, brain scans can help to show that a problem is medical and not moral, as in drug addiction. The good news is that our brains can change even through simple changes. These can be better food choices, brain-supporting supplements like fish oil and magnesium, and brain-friendly exercise.

Computed tomography (CT) brain scan

A computed tomography (or CT) scan of the brain is another non-invasive, imaging technique that uses X-rays to produce a series of slices or pictures. The slices then combine to produce a two-dimensional image of the organ of interest, such as structures in the brain.

Computed tomography (CT) scan technologist overlooking a female patient entering a CT scanner

CT scans can be done with or without what’s called contrast, which is a liquid that can help to see an organ more clearly.

Magnetic resonance imaging (MRI) brain scan

A brain scan using magnetic resonance imaging (MRI) also produces clear pictures of the structures inside our brains. An MRI uses radio waves and is considered the most sensitive imaging by leading hospitals like the Cleveland Clinic.

An MRI can help with understanding of what’s going on if you experience frequent migraines, bad headaches, dizziness, seizures or extreme tiredness.

Brain structures seen through four MRI scan images
Brain structures seen through MRI scan images

What is a functional MRI (fMRI) brain scan

Functional magnetic resonance imaging (fMRI) uses changes in blood flow to produce detailed images of brain function (functional brain imaging). These changes might be missed by other neuroimaging techniques.

MRI does not use X-rays, as CT scans do, but radio frequency pulses. This can be useful if some functions of the brain, like speech or memory, are not working as they should.

Doctor checking testing result from brain imaging

Positron emission tomography (PET) scan

A positron emission tomography (PET) scan uses a small amount of a radioactive drug to show how your biology is working, such as metabolism. For example, cancerous drugs have a higher metabolic activity than normal cells, and that will show up through a PET scan.

The radioactive drug, called a tracer, is usually injected into a vein, as at established hospitals like the Mayo Clinic. The PET scan then be combined with other images, like a CT or MRI scan.

The Mayo uses a PET scan to help to diagnose brain disorders, such as Alzheimer’s disease.

Images from a positron emission tomography (PET) scan of the brain
Images from a positron emission tomography (PET) scan of the brain

Frequently asked questions (FAQs)

Will I need injections for a brain scan?

Yes. You will need an injection for some kind of brain scans, such as a PET scan, which uses a radioactive tracer to show metabolic activity. If you don’t want an injection, consider some of the less invasive brain imaging methods, like SPECT or a CT scan without contrast.

What kinds of doctors usually order brain scans?

PET is most often ordered by doctors who specialize in cancer treatment. Neurologists who focus on the brain and nervous system may also order scans, for example, in the event of brain injury.

More recently, companies like Ezra focus on healthy consumers who want to catch any potential cancers as early as possible. The company has a helpful five-minute quiz to assess your risk for cancer.

How much does a brain scan cost?

Scanning companies like Ezra offer a full-body MRI for about US $2,000. According to Ezra there is a wide range of costs for a brain CT scan, ranging between $825 to $4,800, and a brain MRI costing between $1,600 to $8,400.

Will my insurer cover the cost of a brain scan?

For your insurer to even consider covering the cost of a brain scan, your healthcare professional will need to order it for you for a suspected medical condition. Every insurer is different, so it’s worth checking with your insurer first before having any imaging done.

Can I use my Health Savings Account to cover the cost of a brain scan?

A Health Savings Accounts (HSA) is a type of savings account that lets you cover some medical expenses. You can put money into an HSA before tax, which makes them an attractive way to pay for medical expenses.

Each year, the Internal Revenue Service (IRS) publishes guidance on what procedures and costs an HSA can cover. The published guidance in 2023 covered X-rays.

New companies, like Truemed, are helping consumers use the estimated $150 billion locked in HSA funds to buy healthcare, particularly preventative measures.

Do you have any tips for maintaining long-term brain health?

Yes! Diet tips for one. Take a look at my article on healthy brain food snacks.