Common clinical breast imaging methods include breast ultrasound, mammography (mammogram), and MRI. Ultrasound is radiation-free, safe and reliable, and can be performed even in pregnant women. ultrasound is preferred for screening in young women because of the dense glands and rich fibrous tissue. Therefore, the value of mammography for women younger than 35 years of age is not as significant as for women older than 35 years of age. Fibroadenomas, lobular tumors, cysts and lobular hyperplasia are more common in younger women than breast cancer. Ultrasound not only shows these breast diseases more clearly than mammography, but also identifies most of these benign and malignant tumors. Therefore, for young women under the age of 35, breast ultrasound can be the preferred screening method. 2.Mammogram Annual mammogram from the age of 40. As far as the current medical examination is concerned, physical examination alone is not enough to detect all breast diseases, especially those very early breast tumors. It is now internationally recognized that mammography is the most effective means of breast screening. Mammography has been used in Europe and the United States for decades and has been found to be highly accurate in diagnosing early breast tumors that are not clinically palpable, with an early diagnosis rate of 85%. Therefore, experts in the United States recommend that women should start to have mammography screening once a year at the age of 40, and once every 1-2 years after the age of 60. For women who are at high risk of breast cancer, such as those with family history, pre-cancerous breast lesions and those who received radiation during adolescence, the age of starting mammography screening can be appropriately advanced and the interval between screening should be consulted with a specialist. 3.Magnetic resonance imaging (MRI) of the breast is also a very accurate method of breast diagnosis (high specificity). However, it is more expensive and takes longer to perform. It is generally recommended for young women with significant family history (2 or more immediate family members with breast cancer) and for pre-breast-conserving evaluation.