Mammography
Low-dose X-ray imaging of breast tissue. Full-field digital mammography (FFDM) replaced screen-film in the 2000s. Digital breast tomosynthesis (DBT / 3D) — swinging tube arc, ~15 projections, reconstructed as thin-slice 3D — became the clinical standard in the 2010s. Contrast-enhanced mammography (CEM) and dedicated stereotactic biopsy complete the modern modality footprint.
Physics
W-target (most modern) or Mo-target (legacy) X-ray tube with Rh / Ag filtration. Low-energy (25–40 kVp) X-rays produce high soft-tissue contrast at the cost of penetration limits in dense / thick tissue. Amorphous selenium (a-Se) detector with direct X-ray-to-charge conversion is the modern standard; older systems used CsI scintillator on a-Si. Compression reduces motion, evens tissue thickness, and reduces dose at matched detail.
History
- 1960s — early dedicated mammography units.
- 2000s — FFDM displaces screen-film as the reimbursed standard.
- 2011 — Hologic Selenia Dimensions PMA — first commercial 3D tomosynthesis.
- 2013 — C-View synthesized 2D approved (allowed reading of 3D tomo paired with synthesized rather than separately-acquired 2D).
- 2017 — Hologic 3Dimensions succeeds Selenia Dimensions as the current Hologic flagship.
- 2020s — contrast-enhanced mammography (CEM) reaches clinical adoption; AI-aided reading reaches FDA-cleared deployment at scale.
Key specs
- Detector — a-Se typical, pixel pitch 70–140 µm.
- 2D / 3D / synthesized 2D capability — licensed separately on most platforms.
- C-View / SmartMammo / similar synthesized 2D — license-tier variable.
- Stereotactic biopsy — Affirm Prone / Affirm Upright (Hologic) and OEM equivalents; separable license.
- CEM (contrast-enhanced mammography) — separable license; not universal across vendors.
- MQSA-accreditable — mandatory for clinical use in the U.S.
- Compression paddle inventory — standard, spot, magnification, true-lateral, biopsy-localization. Cracked paddles fail MQSA.
Systems
- Hologic Selenia Dimensions (2D + 3D), Hologic 3Dimensions (current), Affirm Prone biopsy table
- GE Senographe Essential, Senographe Pristina, Senographe DS
- Siemens MAMMOMAT Inspiration, MAMMOMAT Revelation
- Fujifilm ASPIRE Cristalle, AMULET Innovality
Clinical applications
- Screening Mammography
- Diagnostic Mammography
- Stereotactic Breast Biopsy
- Breast MRI (sibling modality)
Service and refurb reality
- The detector is the lifecycle. a-Se flat panels age — 5–9 year useful life on units manufactured 2009 or later; 3 years on earlier panels. Detector replacement is the dominant service event.
- Tube is generally a long-lived component; cracked compression paddles are a more frequent operational failure.
- Workstation lifecycle drives many refurb decisions — older Sun-Ultra-class workstations are unsupportable on current software.
- Refurb premium tracks detector age and 3D / C-View / biopsy / CEM license bundle. A Selenia Dimensions with a 2019 detector swap is worth substantially more than a 2017 unit on the original panel.
Regulatory
- MQSA — federal mandate. Every clinical mammography unit requires accreditation; failing the annual physicist survey takes the unit out of clinical service.
- ACR accreditation — separate accreditation framework, broadly aligned with MQSA.
- Annual medical physicist testing — non-negotiable; budget the day of downtime.
- State registration for X-ray equipment.