BI-RADS (Breast imaging reporting and data system) is the American College of Radiology’s recommended Breast Imaging Reporting and Data System. The significance of each classification is as follows: Grade 0: Needs to be recalled and re-evaluated in conjunction with other examinations. This means that the information obtained from the examination may not be complete. Grade I: No abnormalities are seen. Grade II: benign changes are considered and regular follow-up is recommended (e.g., once a year). Grade III: Benign disease is possible, but a shorter follow-up period (e.g., once every 3-6 months) is required. The percentage of malignancy at this level is less than 2%. Grade IV: There are abnormalities that cannot completely exclude the possibility of malignant lesions and require biopsy for clarification. Grade IVa: low likelihood of predisposition to malignancy. Grade IVb: moderate likelihood of malignancy. Grade IVc: high probability of malignancy. Grade V: High suspicion of malignant lesion (almost identified as malignant disease), requiring surgical excisional biopsy. Grade VI: Malignant lesion has been confirmed by pathology.