Before a CT scanning, patients often receive a contrast material in order to increase the clarity of the image. That is why they are asked to restrict food and beverages for several hours before scanning. Contrast material can be injected or drank. It is important to notify the physician and the staff if the patient has an allergy to iodine or to other contrast material.

Also, the doctor should be informed of any known allergies, history of chronic diseases, surgical interventions and the current medications, including the herbal ones. For the examination, the patient's clothing is replaced with a hospital gown. Jewelry, belts and any metal objects are being removed, in order to avoid interference with image results. During the scanning, it is very helpful to minimize body movements as possible and to follow the technologist's requests to breathe or to hold the breath.

If patients suspect possible anxiety caused by claustrophobia, that should also be an information to provide before the scanning. In case anything should occur and the patient needs to signal that, some system of communication- like an intercom system, may exist in the room.