I do not know about PET scan results but I do know about Bobs experience in healing and at three months it was the first time he actually thought he MAY have really tasted something ..besides coffee which he was not all that fond of before treatment but for some reason was the first "taste" he really enjoyed after. So many things "burned him" as he described it or just tasted funny. It took at least a year before he was close to having most things taste the way he remembered them, and much longer before some things that seemed bland to me were tolerable him to like anything with vinegar in it even ketchup!! So do not be discouraged!! It takes a long time but it truly does continue to improve in tiny steps every day over that long time!