CT for three-month-old infants may cause tumors in infants, increased incidence of blood system diseases and other hazards. CT is to scan and image the human body through the principle of radiation, after the radiation scanning, it will produce certain radiation to the human body, and infants may have a higher sensitivity to radiation than adults, which may lead to cancerous changes in the cells of the infants and the emergence of tumors. CT examination may also inhibit the infant’s blood system, so that the bone marrow hematopoiesis is affected, which may lead to changes in the three lineages in their blood routine, and in severe cases, may induce leukemia. CT for three-month-old infants may also affect the infant’s reproductive system if it is not protected during the examination. Therefore, it is generally not recommended that three-month-old infants undergo CT examination, but if the condition requires that the examination must be performed, it should be strictly carried out under the guidance of a doctor.