There are four main types of screening for breast nodules: first, mammography, or mammography, which can be distinguished on the basis of the relative absorption of X-rays by different tissues, and is sensitive to calcifications in the breast and can detect microcalcifications of very small diameter. The second type, breast ultrasound, is painless, radiation-free, and can be performed repeatedly for short periods of time, and is suitable for women of any age and any physiological cycle. However, ultrasound is not as sensitive as mammography for small calcified foci, i.e. mammography, and it is difficult to diagnose microscopic masses in hyperplastic glands and special types of breast cancer. The third type, breast MRI, causes higher resolution of soft tissues and no radiation, and has been widely used in the diagnosis of breast diseases in recent years. Dynamically enhanced MRI can not only show morphological information of lesions, but also provide functional information such as molecular diffusion of blood water supply and cell membrane choline metabolism of lesions, which is a more sensitive means of breast imaging, but it is more expensive. The fourth, breast and medical examination, PET-CT uses the difference in metabolism between normal and tumor tissues to diagnose tumors, which has high diagnostic sensitivity and specificity, and can evaluate tumor lymph node metastasis and systemic metastasis to provide a basis for the choice of treatment plan.