BI-RADS grade 0: need to combine with other tests; BI-RADS grade 1: negative; BI-RADS grade 2: benign; BI-RADS grade 3: benign possible but needs close observation; BI-RADS grade 4: suspicious malignant suggesting puncture biopsy; 4A: low suspicion of malignancy; 4B: moderate suspicion; 4C: high suspicion; BI-RADS grade 5: almost certainly malignant lacking pathological confirmation; BI-RADS grade 6: pathologically confirmed breast cancer.