Dittoing what Weeb said but adding . . .

An MRI is just a snap shot in time. MRI's are only as good as the tech doing the MRI and the radiologist reading the MRI as well as you (and your brain) at that particular time. This is why so many neurologists want to a) see the MRI themselves and b) don't diagnose strictly based on an MRI. It is not like a broken bone.

Our brains move around in fluid and sometimes catching the lesions can be difficult. Spinal lesions are even more difficult to find due to all the "things" in that compact space.

I have had MRI's where the lesions (big ones at that) don't show up. They are still there but for whatever reason on that particular day, they didn't want to be seen. LOL.

The goods on your current MRI is that there are NO active lesions. Congrats!

Does that help any?