CT, whose full Chinese name is electronic computed tomography instrument, is an examination method that uses radiation to scan a part of the human body in cross-section. It is easy to operate, fast scanning time, clear image, and not expensive, and can be used to examine a variety of organ diseases throughout the body, such as head, chest, abdomen and skeletal system, especially for the head, chest and skeletal system, has a diagnostic value that cannot be replaced by other examination methods. However, any method has its disadvantages, and CT has disadvantages because it uses radiation, so there is a certain amount of radiation to the human body, so you must pay attention to protection during the examination, especially for pediatric patients.