Every once in a while, sometimes once a week, sometimes once a month just before i go to sleep i hear things in my head, mild auditory hallucinations, besides these hallucinations i have headaches every day, very strong headaches, more than 10 hours each day. Now i am going to take a PET scan to find the causes for the headaches and was wondering if at that exact time i am under the scanner and no headache is present and no hallucination, does the scanner still show anything that might be wrong with my brain?