A standardized MRI protocol for brain and spinal cord is crucial for comparing across studies or between centers. T2W MRI cannot distinguish between acute and chronic lesions. Gadolinium provides useful information about new lesion activity and is helpful in ruling out alternative diagnoses such as neoplasm, vascular malformations, and leptomeningeal disease. A single gadolinium-enhanced MRI can potentially provide evidence for dissemination in space and time.
An MRI scan can detect MS activity early on , sometimes before an individual experiences any worsening symptoms. MS activity appears on an MRI scan as either bright or dark spots. Typical MS lesions tend to be oval or frame shaped. Healthcare professionals may use a chemical contrast dye called gadolinium to improve the brightness of MRI scan images.
In MS, the immune system attacks and damages the protective myelin coating that surrounds the nerves. Healthcare professionals refer to this damage as lesions. MRI scans can identify lesions that occur due to MS. MS lesions can show white matter inflammation, demyelination , and scarring, or sclerosis. Scans can let healthcare professionals know when lesions are new and growing and potentially how damaging they are to the brain.
A person with clinically isolated syndrome CIS is experiencing the first episode of symptoms that occur due to inflammation and demyelination in the central nervous system. The symptoms of CIS will last for at least 24 hours. CIS does not always progress to another form of MS. People with primary progressive MS PPMS tend to have fewer brain lesions , and the lesions tend to contain fewer inflammatory cells.
They also tend to have more lesions in the spinal cord than people with other forms of MS. A study from found that people with four or more lesions with dark rims were 1. Lesions that appear rimmed on an MRI scan represent ongoing inflammation. The worsening of symptoms is due to the nerve damage that has already occurred. MRI scans do not use radiation.
The technician obtains the scan using a large, tube-shaped magnet. Once a diagnosis of MS has been clearly established, no additional MRI scans are needed for diagnostic purposes.
However, subsequent scans are important for tracking the progress of the disease and making treatment decisions. For example, a healthcare provider may consider disease activity on MRI as well as your clinical symptoms and relapses in order to determine whether the current treatment is effective or a change in treatment needs to be considered. When possible, follow-up MRIs should be obtained on the same scanner as this will help the radiologist and your healthcare provider make a comparison from one MRI to the next.
Sometimes gadolinium, a contrast agent, is injected into the vein during an MRI to help detect areas of new inflammation. Because gadolinium is a large molecule, it normally cannot pass through the blood-brain barrier specialized cells in the blood vessel wall around the brain and spinal cord that prevent substances from passing from the blood stream into the central nervous system.
However, when there is active inflammation, the blood brain barrier is disrupted and gadolinium can enter and highlight the inflamed areas. Spinal cord imaging can identify pathology in the cord. It can also help establish the diagnosis of MS by demonstrating that damage has occurred in different parts of the central nervous system dissemination in space at different points in time dissemination in time.
It is also useful to identify MS activity when symptoms point to a problem in the spinal cord. You may hear about other types of MRI scans that are used for research. Those listed in this article are the most commonly used in clinical care. The strength of the magnet used in the MRI machine is important to the quality of the images.
Magnet strength is measured in Tesla T. Learn More. Watch Video. MRIs can reveal to doctors injuries in joints, cartilage, ligaments, muscles and tendons. In addition to sports injuries, MRIs can be used to evaluate problems with the brain or spine. Whether you are in the process of being diagnosed or ruling out multiple sclerosis or have been living with MS for a while, an MRI is a useful tool for both you and your neurologist.
Diagnosing MS — MRI is used in the diagnosis of multiple sclerosis, but it is not the only diagnostic tool. The initial MRI can be useful in determining whether the patient has a clinically isolated syndrome or as a predictive indicator for MS.
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