Breast Imaging
Lexicon and categories
Use BI-RADS descriptors exactly: for masses record shape, margin and density; for calcifications record morphology (coarse, amorphous, coarse heterogeneous, fine pleomorphic, fine linear branching) and distribution (diffuse, regional, grouped, linear, segmental). Fine pleomorphic and fine linear branching calcifications in linear or segmental distribution suggest ductal carcinoma in situ. Categories: 0 incomplete, 1 negative, 2 benign, 3 probably benign (under 2% malignant), 4 suspicious (4A 2-10%, 4B 10-50%, 4C 50-95%), 5 highly suggestive (95% or more), 6 known malignancy.
Screening
Breast density categories A to D affect sensitivity and the need for supplemental imaging. Digital breast tomosynthesis improves cancer detection and reduces recall. Screening intervals vary between programmes; know the rationale for the age range used.
Ultrasound
Malignant features include irregular shape, non-circumscribed or spiculated margin, hypoechogenicity, taller-than-wide orientation, posterior shadowing and internal vascularity. Ultrasound is first line in women under 40 and in pregnancy.
MRI
Indications include screening of high-risk carriers, problem solving and implant assessment. Kinetic curves: persistent (type I) favours benign, plateau (type II) indeterminate, washout (type III) suspicious.
Traps
Benign and malignant calcifications are easily confused; category 3 does not mean benign; DCIS may present only as calcification without a mass; not every enhancing focus is a lesion.
Rule of thumb
Grouped fine pleomorphic or linear branching calcifications are suspicious (BI-RADS 4 or 5) and require stereotactic biopsy, not short-interval follow-up.