Breast Imaging
Breast Imaging tests screening and diagnostic mammography, ultrasound and MRI interpretation using BI-RADS, and the work-up of calcifications, masses and asymmetries.
BI-RADS
Categories: 0 incomplete, 1 negative, 2 benign, 3 probably benign (under 2% malignancy, short-interval follow-up), 4 suspicious (4A low, 4B moderate, 4C high), 5 highly suggestive of malignancy (95% or more), 6 known biopsy-proven malignancy. Density is reported separately (A-D) because it affects sensitivity and is a risk factor.
Findings
Spiculated masses with architectural distortion are suspicious. Clustered pleomorphic or linear branching calcifications suggest malignancy; diffuse punctate calcifications are usually benign. Ultrasound distinguishes cysts from solid masses and guides biopsy.
Screening
Screening mammography with tomosynthesis reduces recall and increases cancer detection. MRI is reserved for high-risk screening (BRCA carriers, prior chest radiation) and problem-solving.
Worked example
A 54-year-old has a 15 mm spiculated mass with pleomorphic calcifications and skin thickening. This is BI-RADS 5, so proceed directly to image-guided core biopsy with marker placement rather than short-interval follow-up. Reasoning: spiculation plus pleomorphic calcifications gives a high pre-test probability of malignancy.
Traps
Assigning BI-RADS 3 to a spiculated mass; calling all calcifications malignant; using MRI to avoid biopsy; forgetting to state density; failing to compare with prior mammograms.