Patients who had mammogram were confused when they saw the Bl-RADS grading on the examination report, and after listening to the doctor’s explanation, they panicked and suspected that they had breast cancer. What exactly is the Bl-RADS grading system? How is it graded? Can a qualitative diagnosis of benign or malignant breast nodules (breast cancer) be made based on the Bl-RADS classification? In 1992, the American College of Radiology established the Breast Imaging Reporting Data System (Bl-RADS) in order to standardize the presentation of mammogram reports of breast nodules. In 2003, the analysis of ultrasound and MRI reports was also incorporated into the Bl-RADS system, making it more complete and standardized, and it has been widely accepted and used internationally. It is a graded assessment of the severity and risk of breast nodules, which is divided into 7 levels (0-6), of which 4 levels are divided into 4A, 4B and 4C. The “levels” represent increasing severity. The “grades” represent increasing severity. No matter how refined the grading is, the Bl-RADS system is only an imaging assessment of breast nodules and cannot make a qualitative diagnosis! To put it plainly, it only indicates the degree of suspicion of malignant nodules, but not a definite diagnosis! The final diagnosis needs to be determined by pathological examination! Pathological examination! Pathological examination! For example, ultrasound-guided fine-needle aspiration biopsy or surgical excision of nodule pathology. For breast nodules with Bl-RADS grade 4 or higher, surgical excision of the nodule is recommended. The diagnosis is confirmed by a rapid pathology (about 30 minutes) at the time of surgery, and the surgical plan is decided immediately on the operating table based on the pathology report. If fine needle aspiration is chosen, it must be combined with surgery and not delayed too long to avoid metastases. The Bl-RADS system is significant in assessing the benignity and malignancy of breast nodules and provides direction for treatment planning, but it is not a substitute for pathology.