The Move to Digital Mammography
Busy radiology practices that seek to offer digital mammography services must engage in strategic planning to provide an optimal infrastructure to manage the huge image data files produced by these systems, as well as the newly defined workflow.
Digital mammography systems are powerful, and the workstation design is geared towards improving efficiency while providing high-resolution images on 5 megapixel (5MP) monitors mandated by the FDA. Digital mammography is being implemented in facilities of all sizes, ranging from academic medical centers to community hospitals to imaging centers. Health Imaging & IT visited with several that are defining the process.
Outpatient imaging center
Raleigh Radiology Associates is a busy multi-center outpatient practice that replaced four screen-film scanners with two Hologic Selenia digital mammography systems, while maintaining the same 80 patient-a-day load in their digital office.
What is the ultimate benefit? Improved patient care, says Donald G. Detweiler, MD, president of this group in Raleigh, N.C. He describes image clarity, resolution and quality that provides additional information to guide their diagnostic activities that is far superior to screen-film technology.
Although it may take slightly longer to read the images, Detweiler says the advantages of digital mammography so far outweigh any disadvantages and improved patient care drives their appreciation of this technology.
The Hologic SecurViewDX workstation includes R2 Technology ImageChecker computer aided detection (CAD) which permits individual user configuration for hanging protocols and workflow customization. Detweiler explains that when these systems were first installed, the applications technician suggested a specific hanging protocol to view each case in full resolution mode. Although he tinkered with another approach, he laughingly admits he found himself returning to the original configuration because it was most thorough.
Some of the features offered on the SecurViewDX include a digital magnifying glass that permits visualization of image detail at increased resolution to examine fine details, “intelligent” roaming that automatically moves from one quadrant of a breast image to another while passing over any quadrants where no breast tissue is present.
The workstations are configured as dual 5 megapixel (MP) monitors with 1,024 true shades of gray to allow full contrast resolution. Detweiler says he seldom needs to change the contrast and the magnification functionality has proven quite valuable.
University health center
Alberto Goldszal, PhD, director of radiology informatics for the University of Pennsylvania Health System in Philadelphia explains that they are in the midst of revamping their infrastructure to accommodate full entry into digital mammography. Currently they have two GE Healthcare Senographe systems, but in 2008 when they move into a new Center for Advanced Medicine, they will install an additional seven digital mammography systems.
He considers that part of the significant investment in storage and display infrastructure will be avoided by leveraging their GE Centricity PACS for archiving and image management. Once the latest version of Centricity 2.1 is in place, which was scheduled for last month, they should have all of the support they need for storage, networking and interpreting digital mammograms built into the PACS.
Considering that the data set for one mammography exam can be between 20 and 60 megabytes, the storage requirements increase exponentially. Because they store data sets from advanced modalities including CT and MR, careful structuring of the archive and network is essential.
“From an archiving basis in this institution, we generate 12 to 15 terabytes (TB) of digital imaging data per year,” Goldszal relates. “That number is bound to increase once digital mammography is fully functional.”
Beginning last month, they started using an integrated approach managing images from all modalities on their GE PACS with RA 1000 workstations that offer 5MP monitors. The upgraded PACS features a mammography module that permits image manipulation and management. “The GE proposal is that you do not need to invest in a separate workstation, much like we have today, but digital mammograms can be pushed to a regular PACS workstation as long as it has the appropriate display hardware,” Goldszal says. This functionality enables display of prior mammography scans, as well as other modalities that might have been employed for the patient.
Multi-institution health system
Sutter Health Sacramento-Sierra Region in California, which includes hospitals, medical groups, outpatient clinics, long-term care facilities and research centers in more than 100 Northern California communities, is one of the nation’s leading not-for-profit networks of community based healthcare providers.
Linda Womack, BS, CRT, CRA, regional imaging systems manager relates that in the past year they have installed five Siemens Mammomat NovationDR full-field digital mammography systems with syngo MammoReport radiologist reading workstations equipped with R2 ImageChecker CAD. Most PACS monitors are 3MP for diagnostic reading quality, but with mammography, 5MP monitors must be used to display the proper detail. This mammography dedicated PACS coupled with their radiology department Siemens PACS has resulted in seamless integration.
“These images reside long-term on the same archive as the rest of the radiology images,” Womack explains. And one of the challenges clinicians must consider is which images they plan to save “up front.” Womack says that digital mammography produces different algorithms for each image, so there are raw images, finalized images and CAD images. Radiologists must decide which image data sets are critical to their program.
When they implemented PACS two years ago, they installed a 74 TB long-term archive — with 10 TB in use thus far. However, knowing that in the next year, they will have a full year’s worth of digital mammography plus their other imaging studies, she anticipates adding 10 TB or more per year.