For the average person to do 2-3 CT exams a year is not too harmful to the body. Although the radiation used in CT examinations has certain radiation to the human body, but to do a part of the CT scan, its radiation is around 5-10mSv, and a person can receive the radiation value of 100mSv or less each year can be, according to this dose to calculate, 2-3 times CT is absolutely no problem to the body. However, there are some patients because of disease diagnosis or treatment needs, CT examinations may be far more than 2-3 times a year, at this time to weigh the pros and cons, so a few more examinations can also be negligible, patients do not have to dwell on the radiation to the body, after all, the chances of radiation damage is relatively low.