Can a CT scan Diagnose Multiple Sclerosis?

Types of radiology

Magnetic resonance imaging (MRI) has made it easier to diagnose MS and monitor disease progression. Different MRI techniques can highlight specific aspects of the disease and provide different types of information. MRI and radiology tests that healthcare professionals may use for MS include:

• T1-weighted brain MRI: This scan uses contrast dye to detect active inflammation. It highlights new lesions or lesions that are growing. It can also show dark areas that indicate possible permanent damage.
• T2-weighted brain MRI: This type of scan is less useful in detecting old and new areas of disease, but it can help measure total disease progression.
• Fluid attenuated inversion recovery (FLAIR): As a more sensitive scan, this test can help identify brain lesions. It can sometimes differentiate between old lesions and new disease activity.
• Spinal cord MRI: This test can detect lesions within your spinal cord.
• Computed tomography (CT) scan: The CT scan uses radiation and can also detect areas of demyelination, but with less detail than an MRI.

These imaging tests can detect demyelination, active inflammation, and scarring. Additionally, brain and spinal cord MRI and CT scans can help differentiate MS from other CNS disorders — such as tumors, stroke, or infection — that may cause a person to experience similar symptoms to MS.

What to expect during a radiology test

Before your test

There’s not much preparation for an MRI, but there are some important considerations. Due to the strong magnetic field, some conditions may make it unsafe or require special preparation. Let your doctor and MRI technician know if you:

• have any diagnosed medical conditions
• are claustrophobic
• are pregnant
• have an implanted medical device, such as a pacemaker, drug infusion device, cochlear implant, or aneurysm clips
• have tattoos or metal fragments

If you’re claustrophobic or anxious about the procedure, tell your doctor in advance. A mild prescription sedative may help.

For an MRI of your spine, wear clothing that’s easy to change. It’s dangerous to have this test if you’re wearing clothes with metal, such as zippers or snaps, even if you’re only having images taken of your brain. You may need to wear a hospital gown for the procedure.

You’ll remove any jewelry or metal objects and leave them in another room. Most hospitals provide a locker for safekeeping.

Your doctor or facility should provide you with instructions before the day of your scheduled test.

Preparation for a CT scan is similar to that for an MRI. If your test includes contrast dye, you may be asked not to eat solid foods for a few hours before the test.

During your test

Your MRI may be performed with or without contrast dye. A healthcare professional will administer the contrast dye through an IV in your arm. You’ll lie on a table that slides into the tube-shaped MRI machine.

Earphones help you communicate with the technician, who will monitor from another room. An MRI is noisy and you’ll hear loud banging sounds. Some facilities offer music via earphones to help drown out the noise. You’ll also have a call button in case you feel claustrophobic or anxious.

You must remain perfectly still during scanning. Any movement could affect the scans. The procedure is painless, and you won’t feel anything.

The length of the procedure depends on the number of scans and whether you’re having some with and some without contrast dye. It generally takes at least 1 hour but could take much longer.

Like an MRI, the CT scanner doesn’t touch you, and you won’t feel anything. You’ll be required to remain still. The scanner makes some noise as it moves and captures images.

After your test

You’ll be able to dress and go home as soon as scanning is complete. If you have an IV, a member of the healthcare team will remove it.

If you took a sedative, you’ll need someone to drive you home.

Understanding your results

MS was more difficult to diagnose before MRI became available. Detailed images can be helpful in detecting MS lesions. For example, when visualized with T2-weighted images, MS lesions in the brain or spinal cord can appear as white spots.

However, other factors can cause white spots, so having them doesn’t necessarily mean you have MS.

Doctors usually diagnose a single lesion accompanied by symptoms of MS as clinically isolated syndrome (CIS). CIS can sometimes develop into MS.

Multiple lesions may indicate MS. The diagnosis usually requires at least two lesions within your CNS that occurred at separate points in time.

A radiologist will study the MRI or CT scans and prepare a report for your doctor to discuss with you.

Other tests for multiple sclerosis

There’s no single test for MS. To make a diagnosis, your doctor will consider your symptoms and test results. Additional diagnostic tests may include:

• Lumbar puncture (spinal tap): This will check for antibodies sometimes found in people with MS and can help rule out similar conditions.
• Sensory and visual evoked potentials: These study how well electrical signals in your CNS work.
• Blood tests: No blood test can diagnose MS, but they can help rule out several other conditions with similar symptoms.

Takeaway

Radiology scans like MRIs and CTs are useful in helping diagnose MS along with other tests your doctor may order. The scans can show areas that may be affected by the disease and help detect demyelination, inflammation, and scarring.

This can help a doctor diagnose the type of MS you may have. The information from MRI and CT scans can also help with treatment decisions and disease monitoring.

Radiology scans usually take at least 1 hour. Your doctor will inform you of the details of your scan before it takes place to help you prepare for it.

If your doctor suggests a scan, be sure to voice any questions or concerns so you feel comfortable and know what to expect.