The importance of breast examination With the improvement of living standard, the incidence of breast cancer is increasing year by year. In China, the incidence of breast cancer is now the second most common malignant tumor among women, and the age of onset is getting younger and younger. In our hospital, it is not uncommon to find young women in their twenties with breast cancer, and many of them are already in the advanced stage of the disease when the lumps are found. As a non-invasive breast examination method, ultrasound has many advantages such as painless, no preparation, short time, rapid diagnosis, easy identification, non-destructive, and clear display of lesion characteristics, which should be one of the best examination methods for female breast screening. Clinical applications of breast ultrasonography: 1) routine examination of the breast: it can clearly show the normal and diseased subcutaneous structures and localization; 2) examination of breast hyperplasia; 3) identification of breast masses: cystic or solid, benign or malignant; 4) for axillary and supraclavicular lymph node metastasis, ultrasound can also clearly show. What is the difference between color multispectral ultrasound and mammography (mammography)? The advantages of breast ultrasound diagnosis: 1, no emission, easy to use. 2.Identify the nature of the mass. (It is more valuable to identify cystic or solid breast masses). 3. Ultrasound can show the fine structure inside the breast. Which layer has the lesion, can be localized from the ultrasound image. Ultrasound can help to exclude tumors when X-ray shows dense mammary glands. For axillary and supraclavicular lymph node metastases, ultrasound can indicate the presence or absence of lymph node enlargement. Advantages of X-ray breast diagnosis: 1.For breast cancer less than 1cm, ultrasound often shows unclear, but X-ray can detect it. Ultrasound can not easily show the particle-like calcification points or burr-like structures on mammogram, but X-ray can detect and make diagnosis. Therefore, ultrasound and X-ray examination of the breast, due to the different imaging principles and information obtained, each has its own strengths and should be used individually or in combination in order to improve the level of diagnosis of breast lesions.