I am in a discussion with other departments on how to bill the PET scans. I believe that the primary dx should be a cancer code(i.e. 141.9, 162.9, etc). I use the reason and/or indication for the primary dx code and the findings as second and third dx. The other departments say that you should always use the finding dx codes as your primary dx. I have found several sites that say the the primary dx should be the reason for PET scans. Any help would be greatly appreciated