With protection, the amount of X-rays from a chest CT will have no effect on the breast. Chest CT is mainly an examination of the corresponding chest by means of X-ray photography, which is usually used to examine the chest wall, lungs and mediastinum. Through chest CT examination, it can determine whether there are lumps, stenosis, or the size, number and location of lumps in the examined area, and it can also be used for the diagnosis of pulmonary embolism, and it is usually that a woman will not have any effect on her mammary glands if she has chest CT. With protection, a chest CT will not affect the mammary glands. If there is no protection, long-term chest CT irradiation may lead to tissue and organ atrophy, skin cell necrosis, bone marrow suppression, etc. Women who are preparing for pregnancy, pregnant or breastfeeding are not recommended to undergo chest CT as much as possible. The choice of examination program should follow the doctor’s advice, and make all the preparations as required before the examination.