Mammography CAD Comes of Age

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As new CAD technologies emerge and hint of increasing clinical confidence and workflow advantages, the granddaddy of CAD applications—mammography CAD—continues to prove its merit in a shifting breast imaging world. The radiology community has accepted Digital Mammographic Interpretation Screening Trial (DMIST) results and looks forward to new imaging solutions like breast tomosynthesis. During the upheaval, one standard has remained steady; CAD remains a mammographer’s good friend.

Since its introduction in the analog era, CAD has provided a critical second eye, helping mammographers detect more cancers, earlier and in a cost-effective manner. It’s a win-win situation. As more sites transition to digital mammography, CAD transcends its early promise and delivers additional workflow benefits. This month, Health Imaging and IT visits with two mammography CAD pioneers to learn more about the benefits of CAD in the digital era.

Workflow under the microscope

“Digital mammography CAD has simplified life enormously,” reports James Ruiz, MD, a radiologist at Woman’s Hospital in Baton Rouge, La., and user of Hologic’s R2 ImageChecker CAD. The radiology department at Woman’s Hospital first deployed CAD in conjunction with analog mammography in 2003. Analog mammography CAD workflow required a fair amount of technologist time and input. For each study, a tech digitized and analyzed the film and returned it to its jacket and hung the study.

In contrast, digital mammography CAD eliminates the manual processes to streamline workflow and reduce tech manpower needs, says Ruiz. The CAD system automatically analyzes and marks suspicious areas on the digital images without disrupting tech workflow to further boost the workflow benefits associated with digital mammography. Similarly, CAD improves radiologists’ workflow in the digital environment. Ruiz explains, “The CAD marks simply pop up on the digital images. Our eyes never leave the image, so eye fatigue is reduced.” In an analog department, the CAD output is displayed on a separate monitor or on paper, forcing the reader to take his or her eyes from the film to review another image.

The Center for Breast Care at Boca Raton Community Hospital in Boca Raton, Fla., employs a slightly different efficiency model. The center is an early adopter of mammography CAD and deployed iCAD Inc.’s SecondLook Digital shortly after the technology earned FDA approval in 2002. Prior to implementing mammography, the center’s radiologists double-read all mammograms. Since implementing SecondLook, the department has phased out double-reading. “CAD makes us more efficient,” states Kathy Schilling, MD, medical director of imaging and intervention. Today, CAD serves as the second reader, allowing the site to accommodate a substantial increase in mammography volume without a correlative increase in FTE radiologists.

The practice reaps additional efficiency gains by digitizing analog prior studies with iCAD’s TotalLook Mammo Advantage. The system helped the center eliminate roller boards to minimize the stress of the hybrid mammography environment and accelerate the digital implementation.

A final, critical workflow consideration is the looming mammographer crisis, says Schilling. The reality of mammography is that fewer radiologists are entering the mammography field. CAD provides a critical aid as the crisis hits because it can reduce double-reading while increasing the detection rate.

The clinical rationale

Workflow is an important consideration in radiology; however, patient care is the top priority. The research on CAD is clear. “CAD has proven itself time and time again,” asserts Schilling, “It helps find more cancers. At this point, we would not read mammograms without CAD.” Research shows the use of CAD can detect up to 20 percent more cancers, and help detect nearly 75 percent of actionable missed cancers.

Woman’s Hospital is one of a handful of U.S. sites that employs a CAD/double-reader model. The hospital’s radiologists have double-read all mammograms since 1988. “Our experience has been consistent with the literature. Double-reading increased our detection rate by about 10 percent,” reports Ruiz. The math has changed a bit in the last five years. Today, the contribution of a second reader increases lesion detection by about 6 percent. “This tells us CAD is helping the first reader pick up more cancers, but not eliminating the contribution of the second reader.” With CAD algorithms on a continuous