Mammography PACS must meet requirements that no other radiology subspecialty faces. It is the only imaging modality governed by its own federal statute, the only one that mandates a specific display resolution before a radiologist can read a case, and the only one where a single study, once tomosynthesis is involved, can be an order of magnitude larger than the 2D exam it replaced. A general radiology PACS handles DICOM storage and retrieval fine. Whether it handles the regulatory, workflow, and reporting layer wrapped around breast imaging is a different question.
This guide covers what sets breast imaging apart: MQSA and ACR accreditation, DBT storage math, CAD and AI integration, prior comparison, BI-RADS reporting, and MQSA’s retention rules, so a practice can evaluate its mammography PACS options with a clear picture of the requirements.
Why Mammography Breaks the General Radiology PACS Mold
MQSA and ACR Accreditation
Congress passed the Mammography Quality Standards Act in 1992, the only federal law that specifically regulates a single imaging modality. Every facility that performs mammography, except VA facilities, must be certified under MQSA and accredited by an FDA-approved body, such as the American College of Radiology. That accreditation reviews equipment, personnel qualifications, and clinical image quality, renewed through annual physicist surveys and annual facility inspections. None of this applies to a general X-ray or CT room, and a mammography PACS sits downstream of that certification: the images, reports, and audit trail it stores have to hold up to inspection.
Display and Viewing Protocol Requirements
Mammography also carries its own display standard. Diagnostic workstations need at least 5-megapixel resolution, typically a dual pair of 21-inch monitors or a single high-resolution fusion display, since standard 2-3MP radiology monitors cannot render the fine microcalcifications that mammographic interpretation depends on. Viewing protocols matter too: craniocaudal (CC) and mediolateral oblique (MLO) views are displayed side by side, current-to-prior comparisons align by view and laterality, and the worklist groups all four standard views into a single case. General-purpose PACS software handles DICOM display broadly, but a mammography-capable deployment needs hanging protocols and display hardware matched to these conventions.
Digital Breast Tomosynthesis: The Storage Shift
DBT changed the storage math for breast imaging PACS more than any development since the shift from film to digital. Instead of one flat 2D image per view, the unit sweeps an X-ray source through a narrow arc, capturing a series of low-dose projection images reconstructed into a stack of thin slices through the breast. Depending on breast thickness and the reconstruction protocol, that commonly works out to somewhere in the range of 50 to 70 slices per breast per view.
Multiply that across four standard views, and the study size grows fast. Storage for the reconstructed slice stack alone is commonly cited in the 10 to 20 times range compared to a standard 2D digital mammogram, and climbs higher still if raw projection images are retained alongside the slices and any synthesized 2D view. A practice adding DBT without accounting for that curve will find its storage budget wrong within a year. OmniPACS is built to scale storage capacity with actual usage rather than fixed capacity in advance, which matters here since DBT volume grows unevenly as adoption spreads, and fixed on-premise storage sized for last year’s 2D-only volume runs out fast once tomosynthesis becomes standard practice.
CAD and AI Integration for Breast Imaging
Computer-aided detection has been part of mammography longer than most radiology subspecialties have used AI at all, and the current generation of FDA-cleared AI algorithms extends that into screening triage and diagnostic decision support. In screening, AI tools commonly flag studies with a higher likelihood of malignancy so they route to the front of a reading queue, or provide a second read to compare against a radiologist’s own impression. In diagnostic workups, AI-assisted lesion characterization can support the same BI-RADS process a radiologist already follows, without replacing it.
None of that works if the PACS cannot pass studies to the AI engine and receive structured results back cleanly. The integration point is standard DICOM: the PACS routes the study to the AI system, and the results, whether overlay marks, a probability score, or a structured report fragment, come back into the same worklist the radiologist is already using. OmniPACS supports this kind of DICOM-based routing to third-party CAD and AI tools, so a practice can layer breast-specific AI onto its imaging infrastructure without a separate integration project.
Why Prior Comparison Is Non-Negotiable
Few radiology subspecialties depend on prior imaging the way mammography does. A radiologist reading a screening mammogram is not just looking for an obvious mass, but for subtle change from the last exam: new architectural distortion, a calcification cluster that was not there before, asymmetry that has shifted. Without a prior to compare against, sensitivity drops and callback rates climb, which is why FDA’s own alternative-standards process addresses facilities that issue an interim “need prior mammograms for comparison” assessment while they track one down.
That makes fast, reliable prior retrieval a core PACS requirement, not a nice-to-have. When a prior study lives at a different facility, retrieving it in time for the same reading session depends on secure DICOM sharing between systems rather than a phone call and a mailed CD. A cloud-based mammography PACS that automatically surfaces a patient’s full imaging history, regardless of which affiliated site captured the prior exam, removes one of the most common sources of delay in breast imaging turnaround.
Breast MRI and Ultrasound in a Unified Workflow
Mammography rarely stands alone anymore. High-risk patients get supplemental screening breast MRI, and dense-breast patients and diagnostic workups routinely add targeted ultrasound. A radiologist correlating a suspicious mammographic finding against an MRI enhancement pattern or a sonographic correlate needs all three studies in the same patient timeline, not three separate logins across three separate systems. OmniPACS builds its worklists around the patient rather than the originating modality, so a mammogram, a breast MRI, and a targeted ultrasound land in one consolidated view regardless of which visit or site captured them, which matters most for high-risk screening and post-biopsy follow-up.
BI-RADS and Structured Reporting
ACR’s Breast Imaging Reporting and Data System standardizes how mammography, breast ultrasound, and breast MRI findings get communicated, replacing free-text impressions with a consistent assessment category and management recommendation.
| Category | Assessment |
|---|---|
| 0 | Incomplete, needs additional imaging |
| 1 | Negative |
| 2 | Benign |
| 3 | Probably benign, short-interval follow-up |
| 4 | Suspicious |
| 5 | Highly suggestive of malignancy |
| 6 | Known biopsy-proven malignancy |
That structure only pays off if the PACS or reporting layer captures it as discrete, trackable data rather than burying it in a narrative paragraph. Structured BI-RADS data lets a facility run its own medical audit, track callback and cancer-detection rates, and feed those figures into a registry like the ACR’s National Mammography Database for peer benchmarking.
MQSA-Compliant Retention
Mammography also carries its own record-retention floor, separate from general HIPAA rules. Under MQSA, a facility must keep mammography films or digital images and reports for at least five years, and facilities weighing what that means for their storage budget can check out OmniPACS services to see how cloud storage costs track with retained volume rather than fixed capacity. If a patient has not returned to that facility for another mammogram within five years, the retention period extends to ten years, since the facility cannot know when she might come back or request her records. State law can extend either window further.
That is a longer retention horizon than most imaging archives are built around, and it compounds with the DBT storage increase described earlier. A facility keeping a decade of tomosynthesis studies, at 10 to 20 times the size of the 2D exams they replaced, needs storage architecture built for that math from the start, alongside the same HIPAA-compliant storage safeguards required for any patient imaging data.
What to Evaluate in a Mammography PACS
Practices adding or replacing a mammography PACS should look past the general feature list and confirm the specifics breast imaging actually requires:
- Verified support for MQSA workflows: accreditation documentation, physicist QC data, and audit trails an ACR-accredited site can produce on inspection
- Confirmed compatibility with 5MP diagnostic displays and CC/MLO hanging protocols
- Real-world storage and throughput testing against full tomosynthesis volume, not average 2D file sizes
- DICOM-based routing to CAD and AI tools, with results returning to the same worklist
- Fast, reliable prior-study retrieval across sites, including outside facilities
- A unified worklist spanning mammography, breast MRI, and breast ultrasound
- Structured BI-RADS capture that supports medical audit and registry reporting
- Retention architecture built for MQSA’s five- and ten-year windows
Deployment model shapes several of these directly. A practice weighing cloud PACS vs. on-premises for its breast imaging program should factor in DBT’s storage curve specifically, since fixed on-premises capacity ages out faster under tomosynthesis volume than it did under 2D-only mammography.
Where a General-Purpose Cloud PACS Fits
It is worth being direct about this: OmniPACS is a general-purpose cloud PACS, not a mammography-specific workstation vendor. It does not manufacture 5MP diagnostic displays, does not replace the ACR accreditation process, and does not build proprietary breast-specific CAD algorithms. What it provides is the imaging infrastructure layer underneath: DICOM storage and retrieval sized for tomosynthesis volume, fast prior-study access across sites, a unified worklist across mammography, breast MRI, and ultrasound, and standard integration paths for the CAD, AI, and accredited display hardware a program still needs to source separately.
For a facility with MQSA certification, ACR accreditation, and 5MP displays already in place, that infrastructure layer is the piece worth getting right, since it determines whether tomosynthesis volume and a decade of retained studies stay accessible or slowly become a storage problem. Facilities scoping that out can review flexible pricing for every need to see how storage costs track with DBT volume rather than a fixed hardware footprint.
Frequently Asked Questions
Does a PACS itself need to be MQSA certified?
No. MQSA certifies the facility, the interpreting physicians, technologists, and medical physicists, not the PACS as a product. An MQSA PACS deployment still needs to support what certification requires in practice: 5MP display compatibility, an audit trail for inspections, and long-term retention that meets MQSA’s five- and ten-year rules.
How much more storage does digital breast tomosynthesis need compared to 2D mammography?
Reconstructed DBT slice stacks are commonly cited at 10 to 20 times the size of a standard 2D digital mammogram, and the gap grows further if raw projection images are retained alongside the slices. Facilities adding DBT should plan storage growth around that multiplier, not 2D-era usage.
How long must mammography records be retained under MQSA?
At least five years, or ten years if the patient has not returned to that facility for another mammogram within five years, whichever is longer. State law can extend the requirement further, and facilities should confirm any additional state-specific retention rules.
Can a general-purpose cloud PACS handle mammography and DBT workflows?
It can handle the imaging infrastructure: DICOM storage, prior retrieval, and multi-modality worklists sized for tomosynthesis volume. It does not replace the ACR-accredited displays, personnel qualifications, or dedicated breast CAD software a facility still needs to meet MQSA requirements.
Mammography is not a heavier version of general radiology. It is a federally regulated specialty with its own display standards, its own reporting system, and a storage curve that DBT makes steeper every year. Getting the infrastructure layer right, so tomosynthesis volume and a decade of retained studies stay fast to retrieve, is worth the evaluation time before a facility commits to a platform.