Breast nodules with clear margins tend to be benign signs, and the absence of blood flow signals is mostly seen in benign lesions, and it is recommended to combine with other descriptions to make a comprehensive judgment. Breast nodule is a breast lump found by palpation or imaging, which may be caused by acute mastitis, breast hyperplasia, fibroma and other benign diseases, or malignant tumors such as breast cancer. Malignant breast nodules such as breast cancer should be invasive with blurred margins, while benign nodules tend to have clear margins. Therefore, clear margins suggest that the nodules are more likely to be benign, but the possibility of malignant tumors cannot be ruled out. Malignant tumors are usually rich in blood flow signals, but some breast malignant tumors show low or no blood supply, and the absence of blood flow signals is usually seen in cysts or solid nodules caused by benign diseases. Therefore, the absence of blood flow signal is more likely to be caused by benign breast disease, and does not exclude the possibility of breast cancer. The absence of blood flow and clear margins both tend to be seen in benign breast disease, but it is difficult to determine the risk of malignancy based on these two items alone, and the patient is advised to combine them with the other descriptions in the report.