Appendicitis CT performance diagnostic criteria are: 1, acute simple appendicitis, appendix thickened and enlarged, diameter is generally >6mm, appendix wall thickening, appendix cavity inside the fluid, gas, part of the appendix cavity inside the fecal stone. 2, appendix periappendiceal abscess can be seen in the liquid density of the mass of the shadow, the wall is thick and the border is not clear, there can be a plane of liquid and gas. 3, perforation of the appendix, can be seen inside the abdominal cavity has a gas image. Appendiceal inflammation in the early stage, when the symptoms are mild CT is not necessarily abnormal, clinical diagnosis of appendicitis can be combined with the patient’s medical history and abdominal examination, abdominal CT can be used as an auxiliary examination, which can identify the abdominal pain whether the right side of the ureteral stone caused by.