GuidelineACRMammography / US / MRIBreast Structured report

BI-RADS

ACR · 5th edition · Updated 5th edition (2013, reaffirmed)

Breast imaging reporting and data system. Assessment categories 0–6 across MG, US, and MRI with lexicon for masses, calcifications, and enhancement.

Applies to

Mammography, breast US and breast MRI in adults

Does NOT apply to

Male breast imaging outside of gynecomastia work-up (limited data)

Modality

Mammography / US / MRI

Evidence

ACR consensus — 5th edition

30-second summary

Assessment 0–6 with modality-specific lexicons for masses, calcifications, architectural distortion and enhancement.

Overview

Breast imaging reporting and data system. Assessment categories 0–6 across MG, US, and MRI with lexicon for masses, calcifications, and enhancement.

Assessment — likelihood of malignancy

Category	Malignancy / management
0 — Incomplete	Additional imaging or prior comparison
1 — Negative	Routine screening
2 — Benign	Routine screening
3 — Probably benign	≤ 2% — short-interval follow-up (6 mo)
4 — Suspicious	> 2% – < 95% — tissue diagnosis
5 — Highly suggestive of malignancy	≥ 95% — tissue diagnosis
6 — Known biopsy-proven malignancy	Ongoing management