CT is the English abbreviation of "computer tomography camera" or "computer tomography". It is the biggest breakthrough in X-ray diagnosis since roentgen discovered X-ray in 1895. It is the product of the combination of the rapid development of electronic computer control technology and X-ray examination photography technology in modern times. CT was successfully developed by British physicists in 1972. It was first used for the diagnosis of brain diseases, and then expanded to the whole body examination in 1976. It is a great revolution in X-ray in radiology. China also introduced this new technology in the late 1970s. In a short period of 30 years, thousands of CT machines of various models have been installed in hospitals all over the country and even at the county (town) level. CT examination has been rapidly developed throughout the country and has become an indispensable equipment in medical diagnosis.

Spiral CT mechanism is mainly divided into the following parts: scanning frame, CT machine ball tube, detector, high voltage generator and computer system. The main body of the CT machine is mainly composed of a generator and a ball tube that generate the X-ray harness, and a detector that receives and detects the X-ray; The computer system mainly includes data acquisition system, central processing system, tape drive, operation console, etc. In addition, the CT machine shall also include image display, multiple cameras and other auxiliary equipment.