Diagnosis of MS means the need to identifty lesions in time and space.
So a relapse affecting a different region of the CNS.
This can be seen with MRI
This can be seen by histology too
Are all lesions round, ovioid?
The uneven shapped lesion is probably the youngest lesion likely to be following the path of a blood vessels, but not round like the older lesions and the light blue ones are probably repair and these are known as shadow plaques.
So lesions in different locations (lesions in space) and as the lesions are different ages (lesions in time)