What are Gadolinium Enhancing Lesions in Multiple Sclerosis?

What Bright Spots Mean on Your MRI

Nurse explaining MRI results
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The purpose of a gadolinium-enhanced magnetic resonance imaging (MRI) scan is to give your doctor an indication of the age of your MS lesions, like whether a MS relapse is occurring now or whether one occurred months ago. 

What is Gadolinium and Why is it Called "Contrast"?

Gadolinium, also called "contrast," is a large, chemical compound that is injected through a person's vein during a MRI scan. Gadolinium normally cannot pass from the bloodstream into the brain or spinal cord due to a layer of protection in a person's body called the blood-brain barrier.

But during active inflammation within the brain or spinal cord — as during a MS relapse — the blood-brain barrier is disrupted, allowing gadolinium to pass through. Gadolinium can then enter the brain or spinal cord and leak into a MS lesion, lighting it up and creating a bright spot on an MRI. 

What is an MS Lesion that "Lights Up"?

If a lesion on the MRI lights up, it looks like a bright spot. These bright spots indicate that active inflammation is occurring, usually within the last two to three months. If a lesion on a MRI does not light up after gadolinium is injected, than its likely an older lesion — one that occurred more than 2 to 3 months ago. In other words, the use of contrast helps a neurologists determine the age of a lesion. 

What Does This Mean for Me if I or a Loved One Has MS?

It's important to understand that a MS lesion seen on a MRI does not necessarily cause symptoms. These are referred to as "silent" lesions.

 Also, not all lesions represent MS, which is why a MRI cannot be used alone to diagnose or monitor a person's MS. Lesions seen on a MRI can be the result of aging or other health conditions like stroke, trauma, infection, or migraine. Sometimes, people have one or more lesions on their MRIs, and doctors cannot explain why.

While it's good to understand your brain and spinal cord MRIs, try not to get too hung up on the number or location of your lesions or spots. It's better to focus on improving your symptoms, feeling good, and keeping yourself as happy and healthy as possible. 


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. Retrieved January 9th 2015. 

DISCLAIMER: The information in this site is for educational purposes only. It should not be used as a substitute for personal care by a licensed physician. Please see your doctor for diagnosis and treatment of any concerning symptoms or medical condition.

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