I have had an mri of my brain a couple of years ago, probably about 4 or so years after I developed POIS. Although I did not have the mri done under 100% POIS I was symptomatic with a lot of brain fog and was almost certain that they were going to find something. Anyways the MRI came out perfect with no abnormalities or growths. Leading me to believe that POIS was all chemical-related.