There is a BI-RADS classification for breast lesions in the breast ultrasound report, how do I understand the meaning of the BI-RADS classification? BI-RADS refers to the Breast Imaging Reporting and Data System (BI-RADS), which is used to describe ultrasound signs of abnormalities such as masses and calcifications in the breast, and gives an estimate of the nature of the lesion based on the ultrasound image of the breast lesion. (1 ) The assessment is incomplete. Grade 0: Further evaluation with other imaging studies (e.g., mammogram or MRI) is required. (2) The assessment is complete for final grading. Grade 1: Negative. There are no positive clinical signs and no abnormalities on ultrasound imaging. Grade 2: benign lesion. Basically, malignant lesions can be excluded. Grade 3: Probable benign lesion. Short-term review (3-6 months) and other further investigations are recommended. Grade 4: suspicious malignant lesion. Biopsy is recommended. The probability of malignancy for this grade of lesion is 3% to 94%. Assessment of grade 4 means that histopathological examination is recommended: fine needle aspiration cytology, hollow-core needle aspiration biopsy, and Yu-operative biopsy to provide a cytological or histopathological diagnosis. Currently, they can be classified as 4A, 4B and 4C. Grade 4A is more likely to be benign, with a malignancy compliance rate of 3%-30%; Grade 4B is more likely to be malignant, with a malignancy compliance rate of 31%-60%; Grade 4C suggests a higher likelihood of malignancy, with a malignancy compliance rate of 61%-94%. Level 5: highly likely malignant, appropriate diagnosis and treatment should be actively taken. A lesion with obvious malignant features on ultrasound sonogram is classified at this level, and its malignancy likelihood is greater than 95%, and aggressive treatment should be initiated with percutaneous biopsy (usually image-guided hollow-core needle aspiration biopsy) or surgery. Grade 6: Biopsy-proven malignancy. This level is used on imaging reviews where the biopsy has confirmed malignancy, but treatment has not yet been performed. The main purpose is to evaluate imaging changes after prior biopsy or to monitor imaging changes before and after surgery and before and after neoadjuvant chemotherapy.