About BI-RADS classification Nowadays, when women get their mammogram, mammogram and MRI reports, they will see the BI-RADS classification in the diagnosis, and they will also see the word ACR. 4. So, what do the BI-RADS classification and ACR 4 mean, and what is their role? BI-RADS is the abbreviation of the English name breast imaging and report data system, which translates to the Chinese name: Breast Imaging and Reporting Data System. It is a standard for breast imaging that is regularly published by the American College of Radiology. Its purpose is to standardize the diagnosis of breast imaging and provide breast surgeons with a clearer and more accurate reference. ACR is the abbreviation of The American College of Radiology, and the Chinese name is: 美國辐射学院, followed by 4 which means the 4th edition. There are 7 BI-RADS classifications, including categories 0-6. BI-RADS classification 0 category means: the situation is uncertain, need other imaging assistance, such as ultrasound reported 0 category, then we need to do a mammography, or magnetic resonance imaging. If the mammogram is reported as category 0, then an ultrasound or MRI is needed, or a special mammogram is needed. BI-RADS category 1: normal breast, no abnormalities found. BI-RADS classification category 2: some benign conditions such as simple cysts of the breast, lipomas, lymph nodes, cumulus cysts, benign calcifications, etc., which do not require special treatment and have no mandatory breast follow-up or review requirements. BI-RADS classification 3: Some benign conditions with less than 2% risk of malignancy, such as complex cysts of the breast, fibroadenomas in young women, etc. Classification 3 does not require special treatment, but requires regular review, every six months, to be maintained for at least 2 years, and then further disposition is decided according to changes in the situation. BI-RADS classification 4: Abnormalities are suspected and the patient needs to be advised for further puncture or excision for pathological examination. Classification 4 is further divided into 4A, 4B and 4C,4A is more inclined to benign and 4C is more inclined to malignant. BI-RADS classification 5: Highly suspicious of malignant manifestations, with a probability of malignancy greater than 95%, requiring active treatment. BI-RADS classification 6: malignant tumor that has been confirmed by pathological examination and requires further treatment for a limited period of time.