I. Mammography. Conventional positions include bilateral medial-lateral oblique (MLO) and cephalic foot position (CC). For those who do not show well in the conventional position or do not have the whole breast parenchyma, supplementary positions can be chosen according to the location of the lesion. To make the lesion display better, some special photographic techniques such as local compression photography, magnification photography or local compression magnification photography can be carried out when necessary. Indications: 1, breast lumps, sclerosis, nipple overflow, abnormal breast skin, local pain or swelling. 2, Abnormal changes found by screening. 3, Short-term follow-up of benign lesions. 4.After breast repair and reconstruction surgery. 5.When breast tumor is treated. 6.Other cases that require radiological examination or consultation with radiologists. Mammography is not recommended for women under 35 years of age with no clear risk factors for breast cancer or no abnormalities seen on clinical examination. Breast ultrasound. For all people with suspected breast lesions. Both breast and axillary lymph nodes can be examined. The breast ultrasound scan is performed in the supine position, from the top of the axilla to the lower border of both breasts, including the whole breast and the axilla. Indications: 1. Preferred imaging for breast lesions in young, pregnant and lactating women. 2.Confirmation of clinically palpable masses and suspicious abnormalities and further evaluation of clinical and imaging findings. 3.Evaluation of breast lesions after implantation of prosthesis. 4.Guiding interventional operations. 3.Magnetic resonance imaging (MRI) of the breast. MRI is not used as a routine examination for breast cancer diagnosis. It can be used for breast cancer staging assessment, determining the extent of ipsilateral breast tumor, and determining whether there are multifocal or multicentric tumors. It can be used to screen for contralateral breast tumors at the time of initial diagnosis. It is also useful to assess the extent of tumor before and after neoadjuvant therapy, the status of treatment remission, and whether breast-conserving treatment is possible.