Multiple sclerosis progressively damages the myelin sheath, a protective coating around the nerve cells in the central nervous system (CNS). Over time, this demyelination slows and even prevents the transfer of nerve signals between the brain and the body.

This damage is visible on imaging scans, so advanced imaging can be used to diagnose multiple sclerosis. This article reviews what MS looks like on imaging scans and what to expect during imaging procedures.

MS Diagnosis

MS symptoms can mimic many other health issues. It’s very difficult to diagnose MS without advanced imaging, such as magnetic resonance imaging (MRI), the gold standard for detecting demyelination.

Computed tomography (CT) scans may also help rule out other neurological conditions and diagnose MS. However, CT scan images provide less clarity than MRIs.

Although physical assessments and other laboratory tests may be used to help diagnose MS symptoms, they cannot provide a diagnosis alone.

The main strategies used to diagnose MS are:

  • Neurological exam
  • Past medical history
  • MRI
  • Blood test (to rule out other conditions)
  • Lumbar puncture (spinal tap)

Advanced Imaging for MS

There are two types of advanced imaging tests that can be used to help diagnose MS.

Magnetic Resonance Imaging

An MRI is a noninvasive diagnostic technology used to capture images almost anywhere in the body. MRI equipment produces three-dimensional anatomical images using large, powerful magnets and radiofrequency.

The MRI magnets create a field that forces protons (subatomic particles) in the body to align with them. Radio waves are then used to stimulate protons and cause them to pull away from the magnetic field. The radio waves are stopped, and the MRI equipment captures an image as the protons realign with the magnetic field.

Computed Tomography Scan

A CT scan is another type of noninvasive diagnostic equipment. Instead of taking just a single X-ray, a CT scan rotates around the body and produces several X-ray “slices.” The slices are then digitally stacked to form three-dimensional images of a patient’s anatomy.

What to Expect During Imaging

Although an MRI and a CT scan are different types of diagnostic imaging, the process is similar for both.

Safe and Painless

These tests may sound complex and even frightening, but both MRI and CT scans are completely safe, painless, and noninvasive. Healthcare providers are trained in operating them and using the images to establish a diagnosis for many different kinds of conditions.

Before starting, patients will remove clothing and jewelry and put on medical scrubs or a medical gown. Patients lie down on a table and are moved into a well-ventilated scanning machine. Both imaging procedures are painless, and the equipment does not touch the body.

Some patients may feel claustrophobic during imaging, especially during an MRI. Talk to your healthcare provider about how to manage claustrophobia before your scan.

In some cases, an intravenous contrast dye is used during imaging to improve the visualization of vessels, organs, and other anatomy.

What Does MS Look Like on an MRI?

An MRI uses magnetic fields and radiofrequency to measure water content in the body’s tissues. Since the myelin that protects nerve cell fibers is fatty, it repels water. An MRI can show where MS has damaged the myelin because the fat is stripped away in those areas, and the areas hold more water.

Main Differences Between MRI and CT Scan

The primary differences between an MRI and a CT scan are:

The clinical appearance of MS on an MRI can differ depending on the type of MS.

Brain

Lesions in the brain will appear as light or dark spots that don’t look the same as normal tissue. It is also possible for an MRI to show lesions on the brain and not the spinal cord. The reverse is also true.

MS Lesions on the Brain

Lesions show up on an MRI scan as either a bright white spot or a darkened area. This provides valuable information to healthcare providers about MS diagnosis and the severity of the condition.

Spine

Lesions in the spine will also appear as light or dark spots.

In a 2018 study, researchers reported different patterns for brain and spinal lesions in people with either progressive or relapsing-remitting MS.

One of the main differences was that people with primary progressive MS have more spinal cord lesions than brain lesions. The researchers also noted that those with more spinal cord lesions on an MRI experienced more significant physical disability.

Summary

Advanced imaging of the brain and spinal cord is a critical tool in diagnosing MS. MRI and CT scans are the primary imaging tests used to help diagnose MS. Lesions in the brain and spine appear as lighter or darker spots that appear different from normal tissue. Other types of diagnostic testing, such as a lumbar puncture or blood tests, can also help establish an MS diagnosis.

A Word From Verywell

Experiencing neurological symptoms can be a frightening experience. Advanced imaging such as an MRI or CT scan may seem complex and scary, but both are painless and noninvasive. If you feel nervous about advanced imaging or have a history of claustrophobia, talk to your healthcare provider about the best options to help you cope with the procedure.

Frequently Asked Questions

  • What does MS look like on an MRI?
  • An MRI can show where MS has damaged the myelin sheath because the fat is stripped away in those areas. In a typical fatty myelin sheath, the areas hold more water. These spots show up on an MRI scan as either a bright white spot or a darkened area, depending on the type of scan used. This provides valuable information to healthcare providers about MS diagnosis and the severity of the condition.
  • Can MS lesions disappear?
  • There is no cure for MS. However, a 2018 study reported that brain stem lesions in MS patients could disappear on subsequent imaging and, in some cases, may delay an MS diagnosis. The findings indicated that more weight should be given to the reported clinical brain stem events during an initial diagnosis of MS.
  • Where are most MS lesions found?
  • Researchers in a 2018 study reported different patterns for lesions in the brain and spine of people with either progressive or relapsing-remitting MS.They found that people with primary progressive MS had more spinal cord lesions than brain lesions. The researchers also noted that those with more spinal cord lesions on an MRI experienced more significant physical disability.

An MRI can show where MS has damaged the myelin sheath because the fat is stripped away in those areas. In a typical fatty myelin sheath, the areas hold more water. These spots show up on an MRI scan as either a bright white spot or a darkened area, depending on the type of scan used. This provides valuable information to healthcare providers about MS diagnosis and the severity of the condition.

There is no cure for MS. However, a 2018 study reported that brain stem lesions in MS patients could disappear on subsequent imaging and, in some cases, may delay an MS diagnosis. The findings indicated that more weight should be given to the reported clinical brain stem events during an initial diagnosis of MS.

Researchers in a 2018 study reported different patterns for lesions in the brain and spine of people with either progressive or relapsing-remitting MS.