Understanding Your MRI in Multiple Sclerosis

Black Holes and Bright Spots on Your MRI

MRI Images on a tablet
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A magnetic resonance imaging test, or MRI, is an imaging test used to diagnose MS. In addition to diagnosis, MRIs are also used to evaluate disease progression, like providing an indication of how well a person is responding to their MS disease-modifying therapy. A person may undergo an MRI of their brain and/or spinal cord, depending on his or her symptoms.

The two types of MRIs used to understand a person's multiple sclerosis are the T1-weighted and T-2 weighted scans.

 

What is a T1-Weighted MRI?

A T1-weighted magnetic resonance imaging (MRI) scan shows hypointense lesions, also referred to as “black holes,” because they appear dark on the images. These "black holes" may represent areas of permanent myelin and axonal damage or loss, especially if they are very dark. In other words, the darker the spot, the more damage has been done.

When myelin and axons are damaged or destroyed, nerve cells cannot communicate to each other efficiently or at all—this is what causes a person's unique MS symptoms. 

It's important to note that in addition to permanent axonal loss, a "black hole" or T1-weighted lesion may represent areas of edema, or swelling, which are temporary and disappear on subsequent scans. This is why a neurologist will often compare your current MRI with old MRIs—to see if lesions have resolved.

What is a T2-Weighted MRI?

The T2-weighted magnetic resonance imaging (MRI) scan shows the total number of MS lesions.

This a good indication of a person's MS disease burden over the prior year. The MS lesions on a T2-weight MRI show up as hyperintense lesions, or "bright spots" and are often referred to as plaques. If plaques continue to become re-inflamed, they may eventually turn into "black holes." That being said, sometimes plaques can heal, repair themselves, and disappear.

What Does It Mean to Receive Contrast?

While a person is undergoing a MRI, the MRI technician may give them a contrast through their vein called gadolinium. If gadolinium enters a MS lesion on an MRI, it will light up. A lesion that lights up indicates an area of active MS-related inflammation, meaning demyelination has occurred within the last two or three months.

A Word From Verywell

It's important to understand that MRI is a tool used by neurologists to diagnosis MS and see how well a person is responding to treatment. But lesions on MRI do not always perfectly correlate with a person's symptoms, and more lesions on MRI does not necessarily mean more severe MS-related disability.

This is why a neurologist tends to focus on how a person feels and functions in their everyday life. In other words, treating the patient, not necessarily what their tests or brain images show. 

That being said, research suggests that "black holes" do appear to be associated or linked to a person's functioning and disability—at this point, the nerve damage and destruction is maxed out.

Sources:

Birnbaum, M.D. George. (2013).Multiple Sclerosis: Clinician’s Guide to Diagnosis and Treatment, 2nd Edition. New York, New York. Oxford University Press.

Giorgio A et al. Relevance of hypointense brain MRI lesions for long-term worsening of clinical disability in relapsing multiple sclerosis. Mult Scler 2014 Feb;20(2):214-9

National MS Society. Magnetic Resonance Imaging.

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