CT as a special examination, it is closely related to the preparation before the examination, in order to ensure that patients are able to complete the CT examination smoothly and improve the correct rate of diagnosis, the following matters should be noted: 1, to do CT examination need to carry relevant cases and examination data for reference; 2, remove the high density or metal objects on the body before the examination, such as belt hard buckle; 3, before the CT examination of the abdomen, should fast for 4 hours 4, before CT examination of the gallbladder, fasting should be done 12 hours in advance and must be done in a fasting state; 5, when conducting chest and abdominal examinations, the air should be closed as much as possible to help improve image quality and reduce motion artifacts; 6, women should not undergo pelvic examinations during menstruation CT examination; 7, critically ill patients need to be accompanied by family members and relevant medical personnel; agitated, uncooperative patients should be sedated in the relevant departments before examination; 8, CT examination is radioactive, pregnant women are prohibited from CT examination, infants and children should be examined with caution, and if necessary, radiation protection must be provided for sensitive areas. Patients suffering from drug allergy, heart, liver, kidney and other organ failure should not do enhanced scanning; signed informed consent is required for enhanced CT; 9. After the examination, please go to the self-service film machine to collect the film and report with the barcode as required, and special examinations are appropriately delayed; 10. Special examinations need to be booked, and if the examination cannot be done on time, advance notice should be given, and if there is machine failure or other reasons, resulting in the examination not being carried out, it needs to be rescheduled 11. Keep the CT films properly for comparison at the next review.