Mammography

Low-dose X-ray imaging of breast tissue. Full-field digital mammography replaced screen-film in the 2000s. 3D tomosynthesis (swinging tube arc, 15 projections, reconstructed as thin-slice 3D) became clinical standard in the 2010s.

Physics

W-target or Mo-target X-ray tube with Rh / Ag filtration. Low-energy (25–40 kVp) X-rays produce high soft-tissue contrast. a-Se detector with direct conversion. Compression reduces motion, evens tissue thickness, reduces dose.

History

• 1960s — early dedicated mammography units.
• 2000s — FFDM displaces screen-film.
• 2011 — Hologic Selenia Dimensions PMA — first commercial 3D tomosynthesis.
• 2013 — C-View synthesized 2D approved (replaces separate 2D exposure).
• 2017 — Hologic 3Dimensions succeeds Selenia Dimensions.

Key specs

• Detector — a-Se typical, pixel pitch 70–140 μm
• 2D / 3D capability — licensed separately
• C-View — synthesized 2D (licensed)
• Stereotactic biopsy — Affirm (Hologic) and equivalents
• MQSA accreditable — mandatory for clinical use

Systems

• Hologic Selenia (2D), Selenia Dimensions (2D+3D), 3Dimensions (current)
• GE Senographe Essential, Pristina
• Siemens MAMMOMAT Inspiration, Revelation
• Fujifilm ASPIRE Cristalle

Service reality

The a-Se detector ages (5–9 year useful life). It's the dominant service cost. Every other part is cheaper. Annual MQSA physics testing is non-negotiable.

Regulatory

MQSA — federal mandate. ACR accreditation. Annual medical physicist testing. State registration for X-ray equipment.