CT scanners are specialized scanning devices that use X-rays and computer processing to produce images of the body in cross-sections. These scans are also called CAT scans, or computerized axial tomography. The advent of CT scanners improved the comfort of patients because they operate quite fast. These devices now produce images of extremely high resolution, which makes it easy for a doctor to diagnose a condition. Doctors commonly use CT scanners to search for small, newly formed tumors that would not be detected by standard X-ray film.