September 25, 2023
September 22, 2023

What Is a Normal Brain MRI and When Do You Need Further Evaluation?

Reviewed By:
What Is a Normal Brain MRI and When Do You Need Further Evaluation?

The human brain is an intriguingly complex organ that controls much of what we do—and magnetic resonance imaging (MRI) is a useful tool for getting a detailed look at the brain and its surrounding structures. Here, we’ll go over some basic brain anatomy and function, what a normal brain MRI looks like, and some abnormal findings that can be discovered on an MRI machine.

Brain Anatomy and Function

Human brain anatomy infographic

The human brain is perhaps the most amazing organ in our bodies. It functions as our body’s control center, regulating every process from emotions to movements, breathing to temperature. The brain and spinal cord make up the central nervous system (CNS).

The anatomy of the brain can be broken into three sections: the cerebrum, cerebellum, and brainstem. The cerebrum is divided into hemispheres and lobes. Each lobe has different functions. The brainstem links the cerebrum with the spinal cord and contains important structures, including the pons and the medulla oblongata.

Brain tissue is made up of cells, which includes neurons and glial cells. The brain then has two distinct regions: gray matter and white matter. The outer layer is gray matter while white matter is the inner layer. Gray matter is mainly comprised of neurons while white matter is composed of axons that form the connections between neurons. Axons are then coated in a protective layer called myelin, which helps transmit the messages faster between neurons. 

Gray matter is responsible for processing information such as movement, speech, and sensation. White matter is responsible for communicating that information between other areas of gray matter and throughout the rest of your body. 

What Is a Brain MRI and What Can It Show?

MRI is an imaging test that uses magnetic fields and radio waves to generate detailed images of certain parts of the body. MRI is incredibly useful when it comes to brain imaging because it can produce some of the best pictures of the brain and its surrounding structures.

Compared to other types of neuroimaging, or brain scans such as computed tomography (CT), MRI poses no radiation risk and is completely safe. A brain MRI is able to capture images of your brain, blood vessels, inner structures of your ears and eyes, and bones, including the skull and facial bones. An MRI can also show the ventricles, which contain cerebrospinal fluid (CSF).

An MRI study of the brain can show early evidence of abnormalities of both gray and white matter, including measures of cortical thickness (measuring the thickness of the brain in different areas), and gray matter volume.

A typical MRI brain scan can take 30 to 60 minutes. However, with the Ezra Full Body Scan, you can get an MRI scan of your entire body in just one hour.

Images From Every Angle

An MRI of the brain not only produces high-quality images of the brain, but it can do so at multiple angles, or planes. MRI images are captured in views called axial, coronal, and sagittal views. 

The axial view refers to images that divide the brain into top and bottom while the coronal view refers to horizontal views. Sagittal views mean images from the midline, or side. The sagittal is also sometimes called the longitudinal plane. These different views are important because all of them can provide detailed information about a particular area of concern on a brain MRI, which can help radiologists detect various conditions.

Different Types of Brain MRI

There are also different types of brain scans. A typical brain MRI can be done with or without intravenous contrast. The contrast agent, gadolinium, can be indicated when certain medical conditions are suspected. Magnetic resonance angiography, or MRA, can be done to obtain detailed information about the blood vessels in the brain. 

Functional MRI, or fMRI, can be done to measure brain activity or blood flow in certain areas of the brain. Your healthcare provider will choose which MRI is best for you based on what they are looking for.

How Do You Know If You Have a Normal Brain MRI?

Normal brain MRI: doctor happily talking to a patient

After your MRI scan, a radiologist will read and interpret the images. Once your MRI report is complete, usually your healthcare provider who ordered the test will notify you with the results. Depending on how long it takes for the radiologist to go over your report and for your provider to receive your results, this could take as little as a few days up to two weeks. 

Most of the time, brain MRI reports come back normal. In fact, a recent large study looking at the reports of 16,400 brain MRI scans found that 83% of the findings were completely normal

Are White Spots on Brain MRI Normal?

White spots on the brain, also known as white matter hyperintensities, can mean many things. These can be seen on an MRI scan in people with no symptoms. In the past, white spots on the brain were seen as normal signs of aging. 

However, improved MRI technology shows that white matter hyperintensities can mean there’s decreased blood flow in the area. This can be related to various medical conditions including:

  • Autoimmune conditions, such as lupus or multiple sclerosis
  • Brain tumors
  • Cerebrovascular disease
  • Infections, such as COVID-19
  • Traumatic brain injury

White matter hyperintensities are also linked to a higher risk of cognitive impairment, dementia, balance disturbances, and depression. While this is still an evolving field of research and there is currently no known method to prevent white matter hyperintensities, smoking is a major risk factor for developing white spots on the brain. 

Along with not smoking, managing other aspects of your health such as blood pressure control, eating nutritious foods, and exercising may also benefit your brain health.

As with most medical findings, early detection of white matter hyperintensities on an MRI of the brain can improve outcomes. Since white spots on the brain can indicate many other conditions, finding them early can get people on the path to receiving the care they need. 

What Is Considered an Abnormal Brain MRI?

Brain MRI has the ability to detect a wide range of conditions. These can include:

  • Brain tumors, including common brain lesions like pituitary tumors, meningiomas, and metastatic disease (cancer that has spread from another part of the body)
  • Cerebrovascular disease, including strokes
  • Hydrocephalus, cerebrospinal fluid (CSF) buildup
  • Neurological and neurodegenerative conditions, including Alzheimer’s disease, Huntington’s disease, and multiple sclerosis
  • Vascular malformations, including aneurysms

What Are the Most Common Brain MRI Findings?

Normal brain MRI: father carrying his daughter

Because MRI scans of the brain are detailed, it’s not uncommon for them to detect abnormalities before someone develops symptoms. In one study of first-degree relatives of someone with Alzheimer’s disease, various brain abnormalities were found in over one-fourth of people. These included vascular abnormalities, brain volume loss, and brain tumors. 

While many of these findings increase with age, some abnormalities like aneurysms are just as commonly detected in younger people. When it comes to management, some of these findings are ultimately just observed with frequent follow-up scans. However, some brain tumors (even benign) and aneurysms require surgery before they have the chance to cause any problems. 

From Brain Health to Full Body Health: Early Detection Is Key

Most people will have normal brain MRI results. But when it comes to the detection of brain abnormalities on MRI, the earlier the better. The Ezra scan is a screening imaging tool that can detect abnormalities before you develop symptoms. Early detection is key as it can lead to better outcomes not only for brain conditions but also for conditions involving the rest of the body. 

With Ezra, potential brain masses, fluid collections, and early signs of aging can be detected on brain MRI with the benefit of scanning the rest of the body at the same time. Once you have completed your scan, it will be read by two radiologists, one who specializes in head MRI and one who specializes in MRI of the rest of the body. You can then speak directly to an Ezra clinician to review your results within 7-10 days. 

Take charge of your wellness journey and consider booking an Ezra scan today.