Breast Imaging
Breast imaging tests systematic mammographic interpretation, appropriate use of ultrasound and MRI, and correct BI-RADS communication.
Core rules
- Screening uses two views, craniocaudal and mediolateral oblique; comparison with prior films is essential.
- BI-RADS categories run 0 (incomplete), 1 (negative), 2 (benign), 3 (probably benign, short-interval follow-up), 4 (suspicious, biopsy), 5 (highly suggestive of malignancy) and 6 (known cancer).
- Benign calcifications include vascular, popcorn, rim and diffuse punctate; suspicious patterns are pleomorphic, fine linear or branching.
- A spiculated mass with architectural distortion is suspicious regardless of size.
- Ultrasound is used for dense breasts, palpable lumps and biopsy guidance; MRI for high-risk screening, implants and lobular carcinoma assessment.
Worked example
A 52-year-old has a 1.5-cm spiculated mass on screening. This is BI-RADS 4C or 5, and core biopsy is required. Ultrasound confirms a hypoechoic irregular mass with posterior shadowing. Core needle biopsy, not fine-needle aspiration, provides histology and receptor status.
Traps
- Dismissing clustered pleomorphic calcifications as benign.
- Not comparing with previous mammograms, leading to unnecessary biopsy or missed change.
- Using fine-needle aspiration when core biopsy is needed for receptors.