In fact, mammography and color ultrasound, including MRI of the breast, are common screening tests for breast disease, and mammography and color ultrasound are more commonly used because they are more cost-effective. Both mammograms and ultrasounds have their own advantages and are suitable for different groups of people. Some patients may need a combination of the two to complement and contrast each other. Ultrasound scans of the breast can detect most breast masses, and as the frequency of the ultrasound probe increases, the ultrasound resolving power increases. The ultrasound scan of breast cancer mostly shows a hypoechoic mass with irregular morphology, unclear boundary and uneven internal echogenicity. Color ultrasound can show the blood flow signal inside and around the mass. In addition, ultrasound scan is advantageous in the observation of axillary lymph nodes. A mammogram (often called a mammogram) is also a classic screening test that is performed with a special x-ray machine that takes pictures. Mammograms are more sensitive to small calcifications (which may not show up on ultrasound) and can detect some characteristic calcifications early (such as clusters of sandy calcifications, which may be a sign of breast cancer). However, the accuracy of mammography in diagnosing breast disease is affected by the denseness of the breast glands, and small breast masses (e.g., a few millimeters) may not be distinguishable on mammography. As women age, their breast glands degenerate and their denseness decreases, so mammography screening is highly accurate for women over 40 years of age. In younger women, because of the dense glands and abundant fibrous tissue, the entire breast often appears as a dense shadow and lacks hierarchical contrast. Therefore, breast ultrasound can be the preferred screening method for young women under 35 years of age, especially those who are not breastfeeding. Routine mammograms have a low radiation dose and are not harmful to a woman’s health, but normal women do not need repeated mammograms for a short period of time. Breast MRI is the imaging means with the highest soft tissue resolution and has many advantages over X-ray and ultrasound, such as: reliable diagnosis of multicentric lesions; sensitivity and specificity of more than 90%; lesions that cannot be confirmed by mammography or ultrasound; differentiation between postoperative scars and tumor recurrence; breast cancer patients who want to preserve the breast, find other hidden tumors, clarify the extent of tumors and determine the surgical area; evaluation To evaluate the integrity of silicone implants and breast lesions after breast augmentation. However, breast MRI is not used as a routine examination because it requires high equipment requirements, is expensive, is time-consuming, and requires intravenous injection of enhancer. It is also not indicated for patients with pacemakers and metal in the body. Current evidence does not support tests such as near-infrared scans, nuclear scans, catheter lavage, and blood oxygen testing as screening methods for breast cancer.