Screening Mammography (2D + Tomosynthesis)

Routine bilateral mammographic screening for average-risk women. Two views per breast (craniocaudal + mediolateral oblique, CC + MLO). Since Hologic's 2011 PMA approval for Selenia Dimensions 3D tomosynthesis, tomo has largely replaced 2D-only screening in the U.S.

Clinical rationale

Earlier cancer detection — tomo reduces the masking effect of overlapping dense tissue
Reduced recall rates — 15–30% recall reduction in tomo vs 2D-only (varies by study + population)
Higher cancer detection rate — 30–40% higher invasive cancer detection in dense-breast women
Interval cancer reduction — fewer cancers diagnosed between screening rounds

Workflow

Patient intake — identification, prior-exam retrieval, clinical history
Positioning + compression — tech positions each breast for CC and MLO views. Compression reduces motion, evens tissue thickness, lowers dose.
Acquisition — 2D spot acquisition + tomo sweep (15° arc, 15 projections, 3.7 sec on Dimensions; 2.5 sec on 3Dimensions)
C-View synthesized 2D generated from tomo projections (if licensed)
Radiologist read — typically batched interpretation within 24–48 hours
Reporting — BI-RADS category + recommendation returned to patient + referring provider

Typical systems

Throughput

Room time: ~15 min per patient (including positioning + both breasts)
Daily volume: 25–40 patients typical at high-volume screening centers, up to 50 with efficient workflow
Tech workload: positioning quality is the dominant image-quality determinant

Dose considerations

2D-only dose: ~1.5 mGy per view
Tomo dose: comparable or slightly higher per view vs 2D (1.5–2.0 mGy)
C-View (synthesized 2D): eliminates separate 2D exposure, halves total dose vs combo mode
MQSA dose limits: ACR accreditation tracks dose per view

Regulatory

MQSA compliance mandatory — FDA + ACR accreditation
Annual medical physicist survey
Daily / weekly / monthly QC per ACR program
Tomo + C-View licensed separately from hardware

Equipment considerations that bite

Detector age is the #1 refurb price-determining variable on Hologic Selenia Dimensions / 3Dimensions deals. Clarity HD detector / a-Se panels age 5–9 years on 2009+ generation; 3 years on earlier.
License tier — 3D / C-View / Affirm biopsy / contrast-enhanced (CEM) — separately licensed from hardware. Confirm in writing.
Compression paddle inventory — full set + spares mandatory; cracked paddle = MQSA fail.
Acquisition + review monitors — diagnostic-grade 5MP grayscale; calibration drift is a routine service event.
CAD / AI deployment — third-party (R2 ImageChecker, ProFound AI, iCAD ProFound) vs vendor-native (TransPara, others); reading-workflow integration matters.

Operational reality

Throughput is positioning + room turnover, not acquisition. A skilled tech is the rate limit.
DBT / tomo as standard of care — most U.S. screening programs have transitioned; 2D-only is increasingly atypical.
TMIST trial results (released 2024) reshape evidence base for tomo-only versus 2D-only screening; payer / coverage implications evolving.
Refurb economics — Selenia Dimensions with 2020+ detector swap and current 3D / C-View licensing carries significant premium over original-detector units.