Currently, many neurologists do yearly MRIs to monitor multiple sclerosis disease activity. There is a new blood test that may monitor multiple sclerosis disease activity better in clinically stable patients.
The test is called sNfL (serum neurofilament). It measures the breakdown of a certain part of neurons, which occurs when multiple sclerosis is attacking the nervous system. A recent study (https://nn.neurology.org/content/nnn/7/4/e714.full.pdf) shows that patients with low levels of sNfL have a very low probability of recent MS activity on yearly MRI. This new test may be a convenient alternative to MRI in monitoring disease activity.