MRI scan is the best way to locate
multiple sclerosis (MS) lesions (also called plaques)
in the brain or spinal cord. An MRI scan is abnormal in more than 95% of people recently diagnosed with MS.1
But abnormal MRI results do not always mean that you have
MS. Abnormalities show up on scans from many illnesses other than MS. An
abnormal finding on an MRI scan alone is not enough to diagnose MS. Your doctor
will confirm a diagnosis of MS based on your symptoms, your neurological
exam, and the results from an MRI and other tests.
If you have progressive relapsing multiple sclerosis (PRMS), your condition will get steadily worse from the very beginning.
But you also will experience distinct relapses, with or without full recovery. Between relapses, the disease continues to gradually worsen.
PRMS is the least common type of multiple sclerosis. It affects about 5% of all people with MS.
When abnormal MRI results occur along with a medical history,
abnormal nervous system exam, and other test results that are typical of MS, it
is very likely that you have MS.
If you have already been diagnosed with MS, MRI scans can sometimes
distinguish new lesions from older ones and can help your doctor(s) follow the
progress of the disease. Continuing to have periodic MRI scans if you have
relapsing-remitting MS may help identify new lesions
even when you are not having symptoms from those new lesions.
If you have had just one episode of MS-like symptoms and are trying
to decide whether to start treatment with medicine, MRI scans can be
helpful in assessing the progress of the disease. If new lesions are developing
or if existing lesions are growing—regardless of whether you have had further
episodes of MS symptoms—most doctors will recommend that you begin treatment.