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Breast imaging – Mammography interpretation – Mammography lexicon


The American College of Radiologists (ACR) introduced the BI-RADS lexicon (5th edition; 2013) to standardize breast imaging terminology, reporting, and documentation formats.
Breast imaging interpretation is organized using the BI-RADS lexicon and the BI-RADS classification system applies to mammography, ultrasound, and MRI of the breast.
BI-RADS enables uniform and consistent description of imaging findings. It also allows the radiologist to provide a final assessment BI-RADS category.
The BI-RADS category communicates the provisional diagnosis to the clinician and to the patient for further counselling and management. There are seven final assessment categories, numbered 0–6. BI-RADS 4 has further subcategories, called 4A, 4B, and 4C.
  • BI-RADS 0: Incomplete
  • BI-RADS 1: Negative
  • BI-RADS 2: Benign finding
  • BI-RADS 3: Probably benign
  • BI-RADS 4: Suspicious abnormality
  • BI-RADS 4A: Low level of suspicion for malignancy (> 2% and < 10%)
  • BI-RADS 4B: Moderate suspicion for malignancy (> 10% and < 50%)
  • BI-RADS 4C: High suspicion for malignancy (> 50% and < 95%)
  • BI-RADS 5: Highly suggestive of malignancy
  • BI-RADS 6: Known biopsy-proven malignancy.
Details of the BI-RADS categories with further risk assessment and management recommendations are described in the section on Reporting section.
The mammography lexicon includes descriptions of the following features:


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