Quite honestly, they do not know for sure the significance of T2 lesions to the disease process yet (believe it or not), but what they do know is that people with this certain type of lesion in their brain or spinal cord will likely be dx with MS at some point. That is the main significance of a MRI; to DIAGNOSE the disease.

The more you research and think you understand about this disease, the more you realize "they" don't know a lot either yet. They are not even absolutely sure that repressing the inflammation that goes on in the lesions (causing them to appear less hyperintense in a MRI) is necessarily a good thing . . . but at this point they are approaching them on the premise that the inflammation is bad.

That is the reason that they treat us with steroids and the CRABs, to hopefully reduce the "flare-ups" of T2 lesions . . . in an effort to try to affect the disease process in the longer run. However, other researchers are of the opinion that we should let our bodies "run the course" of inflammation rather then try to suppress it with meds . . .

The way I understand it, the T2 lesions are the more transient type, that inflame and then most often disappear at will. The drugs we use tend to manage the flare-ups of these lesions, but the fact that they are flared does not mean anything absolute either. That's why you will hear people say that they are very disabled with few lesions, and others have no obvious problems with 100+.

Besides, a person could take a MRI every week and get a different outcome of the number of visible lesions.

T1 lesions are the destructive ones, that imply more "axonal loss and matrix destruction." Having them correlates more closely with clinical disability then the number of T2 lesions (which tend to be more transient). T1 lesions are the more permanent (black holes), and are found more commonly in those with SPMS (and possibly PPMS). These lesions generally indicate a longer duration of the disease process, and people with RRMS will generally have a lower ratio of T1/T2 lesions then those with SPMS.

Cherie