Is it possible to have clear mri scans after diagnosis of ms ? after positive spinal tap and lesions on early scans

Yes: Hopefully a sign you're in remission.

Yes: 5 percent of patients with ms do not have lesions detected on mri. Most diagnoses made by history and physical exam. Evoked potentials and spinal tap detecting protein are other possible clues to diagnosis

Very unusual: Ms plaques can go into remission with treatment, but the likelihood of ms plaques completely disappearing from a brain MRI after lesions have been seen on prior MRI scans is very low. Usually, once they are seen on a scan, they do not generally "disappear" on a later scan even if symptoms are successfully treated. They leave a "trace" of their former presence, but they do not cause trouble.

Surprising: Assume you had documented diagnosis years ago. MS can "burn out" in rare circumstances, but usually you would have some lesions persisting, as the T-2 lesions rarely if ever fade. Absence of lesions at this point suggest that you do NOT have MS.