CT scanner. Technicians seen, through the window of their control room, preparing a computed tomography (CT) scanner for use. CT is a diagnostic technique that sends small doses of X- rays through the body at different angles to produce cross-sectional images of the area scanned. The patient lies on the bed and is passed through the hole in the scanner. A computer compiles the X-ray data into multiple image slices. CT scans are widely used to locate tumours, as they are good at distinguishing soft tissue from bone. This is a Toshiba Aquilion scanner.