（The Breast imaging reporting and data system (BIRDS) was proposed and recommended by the American College of Radiology (ACR) in 1992 and has been revised three times since then, and by 2003 it has been used not only to guide mammography diagnosis ( Version 4), but also for ultrasound and MRI of the breast. The diagnostic report of all normal and abnormal imaging conditions of the breast as a whole organ is standardized, using uniform terminology, standard diagnostic categorization and examination procedures, so that the radiologist’s diagnosis can be followed, and at the same time, the coordination and tacit understanding between the radiology department and other related clinical departments is strengthened, so that the clinical treating physicians know what to do next once they read the radiologist’s report. The staging includes levels 0-6: Level 0 means that the lesion cannot be fully evaluated by ultrasound examination, and further imaging is needed for diagnosis. For example: Grade 1 Clinical signs such as nipple discharge, asymmetric thickening, skin and nipple changes, etc., but no signs on ultrasound. Grade 2 Clinical lump detected, age >20 years, with suspicious signs or no features on preferred ultrasound, requiring mammography. Grade 3 MRI is recommended for those who need to differentiate between breast-conserving scars and recurrent lesions after breast-conserving surgery because of the lack of features on both ultrasound and X-ray. Grade 4 For those who need final evaluation before determining treatment Grade 1: Breast imaging shows clear breast structures without lesions showing, and can be confidently judged as not abnormal or normal. The so-called cystic hyperplasia, lobular hyperplasia, and adenopathy (collectively referred to as fibrocystic changes or structural dysplasia), which are commonly diagnosed in our country, are considered normal lymph nodes according to the BI-RADS description of intramammary lymph nodes, anterior axillary lymph nodes showing hypodense lymph nodes or central hypodensity. A clinically detected mass with limited asymmetric changes, despite the final diagnosis of sclerosing adenopathy, cannot be classified as such and may be classified as grade 3 or 4a. Grade 2: Definite benign breast masses (fibrolipid adenoma, lipoma, simple cyst, cumulus cyst, cumulus oilus cyst), definite benign calcifications (e.g., annular calcifications, short streaks of well-defined calcifications, coarse speckled calcifications, sparse, more homogeneous dotted calcifications of a single size, crescent-shaped sedimentary calcifications, etc.), breast nodules with little change in the image on multiple repeat ultrasound examinations, age <40 years Fibroadenomas or fibroadenomas at the age of <25 years on first ultrasound, irregular structures after surgery with no change in the images on multiple reviews, and breast prostheses are all in this category. Annual follow-up observation is recommended. Grade 3: Almost certainly benign. It must be emphasized that this is not an indeterminate type, but it has a less than 2% chance of malignancy for mammography (i.e., almost always benign). For example: (1), a solid oval-shaped mass with clear borders and an aspect ratio <1 at age <40 years is benign with a <2% risk of malignancy. (2), Consider a high probability of fibroma: solid mass with oval shape, clear border, and aspect ratio <1. (3), The original grade 3 (probable benign) can be changed to grade 2 (benign) after 2 to 3 consecutive years of review. (4) Multiple complex cysts or clusters of small cysts. (5), verrucous hyperplastic nodules (in the indeterminate category). (6), Short-term follow-up (3-6 months) and other investigations are recommended for cases of this grade. Grade 4: used to express lesions that require interventional management but are less malignant, with a risk of malignancy of 3 to 94%. (a), Solid masses with non-benign ultrasound manifestations (1-2 items) requiring pathology. Their pathology report is not expected to be malignant, and routine follow-up for 6 months after benign biopsy or cytology findings is appropriate. This category includes some solid masses with palpable and partially well-defined margins, such as ultrasound suggestive of fibroadenoma, palpable complex cysts or suspicious abscesses. (b), including moderately malignant lesions that are suggestive of malignancy. The correlation between radiological diagnosis and pathological findings is close to unanimous. In this case, benign follow-up depends on this concordance. A partially well-defined, partially indistinct mass that may be a fibroadenoma or fatty necrosis is acceptable; however, papilloma requires excisional biopsy. (c), Lesions indicating a moderate to slightly strong suspicion of malignancy that do not yet have the typical malignant features of grade V. These include, for example, solid masses with indistinct borders, irregular shape, or new microscopic, pleomorphic clusters of calcifications. Such pathologic findings are often malignant. (d) For imaging diagnoses of grade IV, regardless of subgrade, there should be regular follow-up after benign pathologic findings. Those with an imaging grade IVC and benign pathological findings from pathological puncture should be further evaluated to clarify the diagnosis. Grade 5: It is used to express lesions that are almost certainly breast cancer. There is a 95% probability of malignancy. Irregularly shaped masses with burrs, segmental or linear calcifications, or irregularly shaped masses with burrs accompanied by irregular and polymorphic calcifications are classified as grade 5. Surgical biopsy is recommended. A standard biopsy without typical malignant lesions is classified as grade 4. Grade 6: This is a new type of grading that is used for the evaluation of images that have been confirmed malignant on pathological biopsy but have not yet been treated. It is primarily used to evaluate imaging changes after prior biopsy or to monitor the effect of preoperative neoadjuvant chemotherapy. Unlike BI-RADS grade 4 and 5, cases at this level do not require intervention to determine if the lesion is malignant.