Infographics / Mammography

Breast compression effects (dose, scatter, thickness)

Two side-by-side mammography diagrams. Left: an uncompressed breast is thick with overlapping internal structures and produces more scattered radiation. Right: a compression paddle flattens the breast to a thinner, wider shape, separating the structures and producing less scatter. A list states that compression lowers thickness, so the automatic exposure control uses lower mAs (lower dose), reduces the scatter-to-primary ratio (higher contrast), separates overlapping tissues, reduces geometric blur and magnification, and immobilises the breast, while total breast volume is essentially unchanged.

Effect of compression in mammography Two side-by-side mammography diagrams. Left: an uncompressed breast is thick with overlapping internal structures and produces more scattered radiation. Right: a compression paddle flattens the breast to a thinner, wider shape, separating the structures and producing less scatter. A list states that compression lowers thickness, so the automatic exposure control uses lower mAs (lower dose), reduces the scatter-to-primary ratio (higher contrast), separates overlapping tissues, reduces geometric blur and magnification, and immobilises the breast, while total breast volume is essentially unchanged. uncompressed compressed X-ray tube more scatter thicker image receptor X-ray tube compression paddle, ~100–200 N less scatter thinner image receptor what reducing thickness achieves Thinner breast: beam attenuated less, so AEC ends exposure sooner at lower mAs — lower dose Shorter path through tissue: less scatter — lower scatter-to-primary ratio, so higher contrast Overlapping tissues spread out and separated — less superimposition of structures Thinner object: less geometric blur (unsharpness) and less magnification Breast immobilised: less motion blur — a secondary benefit, not the prime purpose Same tissue over a larger area: thickness falls but total breast volume is essentially unchanged
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