Digital mammography is a technology rapidly coming to the mainstream despite its demanding nature with simultaneous needs of high spatial and contrast resolution coupled with low dose, summed J. Anthony Seibert, PhD, section head of Digital Mammography at the annual meeting of the Society for Imaging Informatics in Medicine (SIIM, formerly SCAR) in Austin, Texas.
Digital mammography technology has gained clinical trust and consumer interest thanks to the recent results of the Digital Mammography Imaging Screening Trial (DMIST) that found that FFDM is superior in imaging women under 50 and those with dense breasts.
Seibert offered a summary of current digital mammography systems available for sale as well as previewing computed radiography based units pending FDA clearance that are expected to be available as soon as the coming weeks. (CR mammography was part of the DMIST study.) These cassette-based systems will bring with them the pluses of allowing the use of existing mammography equipment with minimal conversion requirements and providing dual field of view – all at a lower cost. This technology uses a cassette-based photostimulable storage phosphor to capture a latent electron image of the transmitted x-rays through the breast which is processed with a CR reader. The cassette, imaging plate and reader are optimized for breast imaging as compared with traditional radiography studies. Seibert opines that while CR mammography offers a quick move to digital mammography with minimal investment, it does bring significant handling of cassettes and depending on the type of reader, single-plate or multi-plate, it can reduce the efficiency of the technologist and reduce overall patient throughput. The x-ray generator also needs to be carefully interfaced.
In contrast to CR-based systems, currently used cassetteless-based digital mammography systems offer higher throughput, lower dose and additional capabilities for advanced acquisition techniques down the road such as digital tomosynthesis.
Early adopters of digital mammography have struggled with the transition from analog-to-digital paradigms, the awkwardness of comparison studies and drops in radiologist productivity due to interruptions in workflow. Some of these productivity issues are due to a lack of a “universal workstation” for similar “For Presentation” appearance of digital mammograms and other adjunctive breast imaging technologies such as breast MRI, Seibert said.
On the horizon are new detectors that “count individual photon events rather than integrating the events as all current detectors do,” he explained.
Seibert urged attendees to keep ahead of the curve in terms of systems, hardware and software to determine whether a move to digital mammography is right for a particular healthcare facility. “There is no distinct overall advantage of any digital mammography system, as each detector has strengths and weaknesses in terms of image quality, dose efficiency, patient throughput, technologist efficiency and implementation costs,” Seibert opined.
PACS is an essential part of the decision as well, requiring careful planning to enable a certain level of desired workflow and efficiency. It also is key to understand MQSA rules regarding the implementation and use of digital mammography systems prior to purchase. A quality control plan also is essential as is a plan for how to view prior exams, namely screen film and soft-copy images.
He also offered several web resources:
- Digital detectors for mammography: www.sunnybrook.utoronto.ca:8080/~yaffe/DIGMAM.html
- DICOM and IHE: www.dclunie.com
- IHE efforts for the digital mammography profile:
- MQSA rules for digital mammography: www.fda.gov/cdrh/mammography/digital.html