In recent years, digital technology has revolutionized the practice of radiology. While many clinical areas within medical imaging have already undergone a widespread migration to digital technology, mammography has been one of the last to embrace this change.
In recent years, digital technology has revolutionized the
practice of radiology. While many clinical areas within medical
imaging have already undergone a widespread migration to digital
technology, mammography has been one of the last to embrace this
change. Recently, however, with the publication of groundbreaking
studies, such as the Digital Mammographic Imaging Screening Trial
(DMIST), which clearly demonstrate the benefits of this technology,
many healthcare facilities have begun to make the move to digital
One healthcare organization that recently began offering digital
mammography is Centegra Health Systems. Located in northeastern
Illinois, Centegra is the region's leading provider of care, with
access to 30 clinical sites. They perform approximately 7000
screening and diagnostic mammograms a year, averaging more than 500
such studies a month.
When Centegra's main campus, Northern Illinois Medical Center
(McHenry, IL), needed a new stereotactic core biopsy unit, they
decided to use that opportunity to make the move to digital
technology. "Through the process of replacing our stereotactic core
biopsy unit, we obtained a full-field digital mammography system,
from Siemens Medical Solutions (Malvern, PA)," explained Donna
Billeck-Gonshorek, RTR(M), Team Leader for the Women's Center at
Northern Illinois Medical Center. This all-in-one system can be
used for screening and diagnostic mammography, geometrical
magnification, high-resolution spot imaging, stereotactic biopsy,
specimen radiography, and galactography. It features a dual-target
X-ray tube, amorphous selenium detector technology, and a large (24
× 29 cm) detector plate, allowing it to image nearly all breast
Installation and integration
Once purchased, the digital system had to be installed and
integrated into the hospital's existing workflow. This process was
not difficult, according to Billeck-Gonshorek. "We had some
software issues at first but it was never a problem with the
equipment or the detector." Most of the issues that arose, she
noted, related to the integration of the new system's software with
existing hospital system, such as the hospital information system
(HIS), radiology information system (RIS), and the picture
archiving and communication systems (PACS).
Once the system was up and running, integration with the
archival system was uncomplicated as well. "Creating an archival
system was not an issue for us because we had already had PACS for
roughly 3 years," said Billeck-Gonshorek. "Therefore, it was just a
matter of buying additional memory since digital mammograms take up
an enormous amount of memory."
Digital mammography as a marketing tool
With the MAMMOMAT
in place, the organization began marketing the benefits of digital
mammography to both its referring physicians and their patients.
"We promote the higher detection rate in the same manner as the
DMIST report," explained Billeck-Gonshorek, "as well as its value
for patients between the ages of 40 and 50 years and for those with
fibrocystic breasts or a history of breast cancer."
More physicians are beginning to acknowledge these benefits, she
noted, and are writing prescriptions specifically for "digital
mammograms." Patients are requesting digital mammograms as well,
although sometimes for the wrong reason. "It seems that there is a
misconception on the part of some patients that there is no
compression with this technology," she said, "so patients want
digital because they think it is going to be less uncomfortable. We
try to explain that it is the filming that is different."
Who gets digital?
With both digital and analog mammography systems available,
decisions must be made as to which technology to use for each
patient. To date, Northern Illinois Medical Center has not set
specific rules regarding which patients receive which type of
mammogram. "If a patient requests a digital mammogram, they are
given one," said Billeck-Gonshorek. "If it is not requested, those
patients who are better candidates for it-those who are
fibrocystic, those between the ages of 40 and 50 years, and those
with a family history of breast cancer-are chosen for digital
first. The remainder are chosen on a first-come-first-served
Benefits of digital mammography
In the first year of using digital mammography,
Billeck-Gonshorek has seen many of the benefits of this technology.
"The images are incredible. I've been doing mammograms for more
than 20 years and it's like night and day to me. With the digital
system, we are able to visualize many more lesions. Some of the
cancers that we are seeing probably wouldn't have been found at the
same time with film. The patients probably would have waited
another year before we caught it on an analog mammogram. That's not
always the case, but that is what we are seeing in our facility.
This increase in diagnostic capabilities is a benefit for the
She is seeing potential benefits for the staff and institution
as well. "For now, we still schedule 1 patient every half hour, but
the workflow eventually will be a lot faster than it was with
analog," she said. "At some point, we may be able to go to 1
patient every 15 or even every 10 minutes with digital mammograms.
With digital, the pictures are instantaneous, so you are able to
see right away if you need to do any extra views. If something is
even questionable, you can do the spot or magnification views
immediately; whereas before, you would have had to take the films,
develop them in the processor, make sure they came out OK, then
take more, go back, and check them again. The digital workflow is
Billeck-Gonshorek found several of the features specific to the
system beneficial as well. For her, one of the most important
innovations was the system's unique flex compression paddle, which
was designed to provide optimum levels of compression for enhanced
image quality while still providing maximum comfort for the
patient. The OpFocus compression plate allows for fast and easy
patient positioning and keeps the breast in the central beam. It
also provides for enhanced visualization of the pectoral
The OpComp feature compresses the breast only as long as the
tissue is soft and pliable and automatically stops at the point of
optimal compression. In addition, the SoftSpeed element slows the
compression plate after its initial contact with the breast and
adjusts the speed according to compression resistance.
's paddle is more comfortable for the patient," said
Billeck-Gonshorek, "and, because it is more flexible, the paddle
provides flatter, more even compression across the entire breast.
In fact, our radiologists have commented on that and have said that
they see a more even compression from the thick chest wall tissue
to the thinner nipple tissue. It is the only paddle I use."
The system's OpDose feature automatically selects the best
anode/filter combination (Mo/Mo, Mo/Rh, or W/Rh) and the lowest
appropriate dose for the individual breast characteristics. This
feature provides an optimized X-ray spectrum for each patient and
reduces both the exposure time and dose while providing enhanced
image quality. Use of the Tungsten tube (W/Rh) provides the same
image quality as the Mo/Mo combination but up to 50% less dose.
Acquisition Workstation and high-speed softcopy reporting
also streamlines workflow. The images are available for immediate
viewing with the
MammoReport, which is capable of loading an 8-image case in <1
second. HIS/RIS and PACS connectivity facilitate digital archiving
with the RIS client running on a separate PC and monitor.
With digital mammography the images can also be manipulated for
optimal viewing. "With analog imaging, once you have a picture,
that's it, it can not be changed," explained Billeck-Gonshorek.
"With digital technology, however, the radiologists can window and
level and manipulate the images as needed. It's phenomenal."
Looking back at the process of installing and integrating
digital mammography into an established analog practice,
Billeck-Gonshorek offers some advice for those who wish to do the
same. "Anyone purchasing a digital system should make sure that all
the systems will talk to one another: PACS, HIS/RIS, and CAD," she
said. "These were the only things that delayed our
She also noted that the process of digitizing prior film images
was more time-consuming and complex than she had anticipated. "If I
knew then what I know now about digitizing previous images, I would
not have done it," she said, "because with our equipment it was
very involved, more than I thought it would be." Another concern
she has about digitized images is the potential for lost detail.
"There might be detail that is lost from the analog image when you
digitize it and you just don't know," she continued. "I think it's
up to each individual facility and the radiologist to decide if
that is something they want."
Overall, Billeck-Gonshorek reports that at Northern Illinois
Medical Center they are pleased with the advances offered by
digital mammography. "The detail our radiologists can see on the
digital mammograms is so much better and they are so much easier to
look at than analog films," she concluded. "Now many of our
radiologists don't even want to read the analog images."
- Pisano ED, Gatsonis C, Hendrick E, et al. Diagnostic
performance of digital versus film mammography for breast-cancer
N Engl J Med
Siemens Medical Solutions USA, Inc.