There is no clear-cut rule on how often a CT examination should be done, and it is mainly based on the needs of the condition. For normal people, a CT checkup at intervals of about half a year to a year will not have a serious impact on the body. CT examination is one of the more widely used means of detection at this stage, mainly using X-rays to scan the cross-section of the human body, and reconstructing the image through the X-rays of the subtle differences in human tissue to determine the disease. Since X-rays are used in the CT examination process, they produce ionizing radiation, and under normal circumstances, the frequency of exposure to X-rays should be minimized; especially pregnant women must avoid exposure to avoid potential damage to the fetus. Although X-rays may cause some damage to human tissue cells, the degree of damage is relatively small, and the examination can be repeated several times if the condition requires. For normal people, CT examination is mainly used as a physical examination program, in which case there is no need to take excessive risks and use the CT examination program frequently. In general, the interval should be greater than six months to one year.