T1-Weighted and T2-Weighted MRIs in Multiple Sclerosis

Black Holes and White 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. 

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 axonal damage or loss, especially if they are very dark. Axonal damage or loss refers to the nerve fibers that are damaged or destroyed in multiple sclerosis. When 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 Does It Mean to Receive Contrast?

While a person is undergoing a a T1-weighted MRI, the MRI technician may give them a contrast called gadolinium. If gadolinium enters a lesion on an MRI, it will light up and create a bright spot on the image.

This indicates an area of active MS-related inflammation. The purpose of contrast is to provide information about the age of a lesion, like whether it occurred within the last 2 to 3 months. 

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. The MS lesions on a T2-weight MRI show up as hyperintense lesions, or "white spots." 

What Does This Mean for Me?

It's important to understand that a MRI is a tool used by neurologists to diagnosis MS and see how well a person is responding to treatment. That being said, lesions on a MRI do not always correlate with a person's symptoms, and more lesions on a 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. 


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

National MS Society. Magnetic Resonance Imaging.

Edited by Dr. Colleen Doherty May 1st 2016.

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