There is no prescribed range for the interval between CT exams, for example, if the first CT is done and there is no problem after a low-dose screening of the lungs, a second one can be done 1-2 years later, depending on the specific situation. If a specific lesion is found, it is possible to do CT again after one or two months. If the effects of CT radiation are considered, the cellular decay may actually last only 1-2 days after radiation exposure. In patients with bleeding, it may be necessary to review earlier, usually after 24 hours. The interval of CT is not usually considered, but is actually within the safe range, because the radiation doses of CT are within the safe range and have no effect on the body.