I doubt the high res MRI would change much. They are used for research. Old injuries would not show up as the damaged tissue would have been absorbed long ago. A fMRI would probably show more. A DTI mri also can image some subtle damage.

3 Tesla MRI's are not uncommon. It takes about 6 Tesla to see the damage common to concussions.

The problem is that imaging the damage does not change the treatment because there are not any treatments of much value besides OT, ST, and VT and the things we do for ourselves.