In the past I had MRI and PET scan for possible TBI. Yes I was nervous to find out results and turned out I have mild TBI and that is why my neuropsychological exam was abnormal. Had to fast before PET scan and it then detected that there was mild hypometabolism in certain of my brain and correlated with my abnormal IQ test scores. Good luck and hope it turns out ok, I can certainly empathize and sympathize, it’s not fun to go through testing and wait for results.