BI-RADS Nomenclature for Mammography and Ultrasound
2.1 Introduction
The American College of Radiologists (ACR) Breast Imaging Reporting and Data System (BI-RADS) has become an integral component of breast imaging reporting. BI-RADS has served as a universal language beginning in the late 1980s, with the first edition of BI-RADS put into practice in 1993. Through the use of the BI-RADS lexicon, standardization and uniformity has been brought to breast imaging reporting. The lexicon takes into consideration the overall features of a mammogram that may interfere with image interpretation such as the breast density pattern. It provides an effective means of communication to discriminate between benign and malignant features through terminology and structured reporting of lesions seen on mammography, ultrasound, and magnetic resonance imaging (MRI). Finally, it aids in imparting an overall assessment of the level of concern for malignancy and the appropriate action that should be taken for patient management. The cases in this text use the terminology of the ACR BI-RADS® Atlas, 5th edition, 1 as they apply to the imaging findings of mammography (which also apply to digital breast tomosynthesis [DBT]) and for corresponding ultrasound imaging when it further aids the findings of DBT. Therefore, to assist in using this text, we have provided the following abbreviated terminology and classification tables ( ▶ Table 2.1, ▶ Table 2.2, ▶ Table 2.3, and ▶ Table 2.4) adapted from ACR BI-RADS® Atlas, 5th edition, for these imaging modalities. These tables are not intended to be comprehensive. For more complete details, the reader should refer to the ACR BI-RADS® Atlas, 5th edition.
Breast composition | The breasts are almost entirely fatty | |
There are scattered areas of fibroglandular density | ||
The breasts are heterogeneously dense, which may obscure small masses | ||
The breasts are extremely dense, which lowers the sensitivity of mammography | ||
Masses | Shape | Oval |
Round | ||
Irregular | ||
Margin | Circumscribed | |
Obscured | ||
Microlobulated | ||
Indistinct | ||
Spiculated | ||
Density | High density | |
