After you arrive for your appointment, depending on the area of your body to be scanned, you may need to change into a gown or pajamas. Some scans may require a contrast agent to help highlight the areas inside your body that your doctor wants to see. This is given in the form of a drink or an injection. Once you are prepared for your exam, the technologist, who is specially trained in imaging procedures, will help position you on the table of the CT scanner. Usually you will lie face up and the table will automatically move into the large donut shaped scanner. While inside the scanner, you will be able to see your outside surroundings. The technologist will talk with you from the control room where they can see you at all times. When you are ready, the scanner is turned on. The ring rotates around your body as it sends and picks up X-rays. It is very important to lie completely still. Periodically, the technologist may use the intercom to ask you to hold your breath for short periods of time. This helps to create better pictures when scanning the abdomen or chest. Most CT examinations take 30 minutes.