Breast CAD Comes of Age

Over the last several years, mammography CAD systems have matured and gained acceptance among radiologists, payors and patients as a standard of care. Today vendors are finding new ways to demonstrate the value of CAD. Breast CAD vendors have always touted CAD solutions as to a way to improve breast cancer detection with improvements in the range of 20 to 25 percent. The latest technology extends the reach of breast CAD - aiming to initiate sites transitioning to digital with efficiency gains and simplified storage solutions.

Breast MRI CAD looms larger as well. In addition to the two dedicated MRI CAD solutions on the market, iCAD markets its 500M viewing solution. The 500M performs CAD on both the breast MRI study and film-based mammogram and displays both on the same viewer. Efficiency is, once again, the name of the game as reading breast MRIs can be a time-consuming undertaking. CAD provides an answer by reducing the time it takes to read a breast MRI from up to several hours to five to 15 to 20 minutes.


CAD & FFDM: THE PERFECT MARRIAGE

Straub Clinic and Hospital (Honolulu, Hawaii) is part of the Hawaii Pacific Health Network, a four-hospital system with an ambitious plan to implement PACS, digital mammography and 3D CT technology. Robert Lipman, MD, staff radiologist, says CAD is a key part of the transition to PACS and digital mammography. Straub Clinic and Hospital installed R2's DigitalNow last summer to pave the way for PACS and digital mammography. "The ability to transfer from film to digital to PACS is the No. 1 reason why we implemented CAD," Lipman says. With DigitalNow, Straub Clinic and Hospital transfers film mammograms to its DigitalNow digitizer to a Fujifilm Synapse PACS. The hospital system also has installed a Hologic Selenia digital mammography system at one hospital and plans to install another three digital mammography systems by the middle of 2005.

Lipman explains the benefits of the hospital's approach. "There are obvious benefits, like discussing findings on a mammogram without needing the physical film. And radiologists and surgeons can talk about the same image without being in the same place. What we didn't realize before we installed DigitalNow are the benefits for procedure planning. When a surgeon is planning a biopsy, he no longer needs to locate the film, which is a real time and workflow savings."

There are other 'surprise' benefits to digitized mammograms, says Lipman. For example, a digitized mammogram can be magnified and enhanced when it is projected in a conference room during a tumor board meeting, providing radiologists and clinicians in all parts of the room a clear view of the case.

Lipman adds another simple, but valuable, plus to the list of CAD benefits. "With every CAD product, the radiologist can be sure he or she is reading and dictating the right mammogram. Techs can put the case on the wrong panel number, and the radiologist can dictate the wrong patient." With CAD, however, if the CAD findings don't match the images, the radiologist knows he or she is looking at the wrong film.

There are cost benefits as well. "The insurance companies are indirectly paying us to digitize films and store mammograms in PACS [by reimbursing for CAD]," Lipman explains. To gain this benefit, sites must retain the initial digitized mammography images; some sites scan twice - once for CAD and once for PACS, which is an inexpensive and overly complicated process. Instead of disposing of the digitized CAD images, Lipman recommends that sites hold them for storage in PACS.

The final benefit with CAD is the computer markings - alerting radiologists to potential lesions. Even with the detection, storage and efficiency gains with CAD, Lipman looks forward to future improvements. "The next great leap in CAD will be the ability to compare mammograms to prior images. I have that advantage; CAD doesn't. I know if a lumpy spot has existed for 10 years and isn't a cause for concern."


CAD & COMPREHENSIVE BREAST IMAGING

Catholic Medical Center (Manchester, N.H.) plans to open a new comprehensive breast center offering both digital mammography and breast MRI next month. iCAD's MammoReader and CAD software is serving as the backbone for the endeavor. The hospital deployed CAD about 18 months ago. Michael Cloutier, manager of technical services, says the technology helps radiologists identify positive findings more quickly and with less clutter than without CAD. But these benefits just scratch the surface of breast CAD.

While the center has realized CAD benefits in terms of improved specificity, the radiology department is looking forward to taking CAD to the next level. The hospital is installing a GE Senographe DS digital mammography system next month. Cloutier explains, "The vision is to take digitized images from our database and send them to the mammography workstation to allow radiologists to view two digital images."

Another option with a similar result is to digitize previous analog mammograms for digital viewing. "The newest image would be diagnostic quality, and the other would suffice for comparison so the hospital could eliminate the film alternator and flat-panel viewer combination," Cloutier continues. "This could really increase the effectiveness of radiologists' workflow and minimize the space required for mammography reading."

Currently, Catholic Medical Center stores six to nine months of historical digitized mammograms on the local iCAD drive, but these aren't pulled up with previous images. The center plans to stores digital mammograms in its GE Centricity PACS to enable digital reading of previous mammograms in the future.

The other piece of Catholic Medical Center's new breast center is breast MRI. Cloutier admits the hospital's radiologists shied away from breast MRI in the past because it represented a tremendous time commitment for diagnosis. The center aims to deploy iCAD's 500M viewing solution for MRI and mammography to overcome this challenge and make breast MRI reading a manageable proposition.


ENHANCING EFFICIENCY WITH MRI CAD

While mammo CAD is focused on improving detection and accuracy, MRI CAD comes to the market with a slightly different angle - efficiency. Justin Hill, MD, staff radiologist at First Hill Diagnostic Imaging (Seattle) points out that breast MRI exams can comprise more than 2,000 images. He explains, "That is onerous without CAD. Although there is no shortage of capacity to acquire breast MRI data, groups don't want to read breast MRIs because the demands on the radiologists' time don't correlate with the reimbursement."

First Hill has relied on Confirma's CADStream breast MRI CAD since December 2002. The CADStream process is simple but the results are powerful, says Hill. At the conclusion of the MRI, data are sent from the scanner to PACS and routed to the CADStream system, which automatically processes the images according to site protocols and the radiologist's reading preferences. The radiologist clicks on the patient and begins reading. In a typical case, the radiologist can read a breast MRI in 15 to 20 minutes with CADStream vs. 2 to 3 hours without CAD, Hill says.

Hill opines, "Efficiency is the single most important tool MRI CAD brings to the table. The system also preserves, and may possibly, improve accuracy." Although mammo CAD is FDA regulated at the pre-market approval (PMA) level, MRI CAD is less stringently regulated at the 510(k) level. Consequently, data about MRI CAD's specificity are not widely available; however, ongoing studies seem to indicate improved specificity.

"Breast MRI is very sensitive, but not very specific," Hill says. "The hope is that MRI CAD can improve specificity without impairing sensitivity. Any system that helps radiologists do a better job [by improving accuracy] and be more efficient at the same time is win-win for everybody."

Hill concludes with a downstream benefit of CADStream; the system can help surgeons visualize tumors and prepare for surgery.
Julian Safir, MD, radiologist with Nassau Radiologic Group (Nassau, N.Y.), has relied on 3TP MRI CAD for nearly a year. He explains, "The technology allows us to characterize what we see on a breast MRI as meaningful or not. We can characterize malignancies vs. benign findings and obviate the need for a biopsy or follow-up exam  saving time and money." Safir's reading time has dropped from 25 to 30 minutes to 5 minutes with 3TP. In addition to improving patient care and saving time, Safir points out, "3TP is reimbursable under a separate code. Plus we're able to give surgeons more accurate reading, so using the technology will likely increase referrals."


CONCLUSION

A few years after its market debut, CAD is still flexing its muscles and finding new ways to demonstrate its value. Breast CAD technology can not only improve detection and clinical care, but now, with the integration of digital mammography and PACS and the ability to perform MRI CAD, its value becomes even more clear. Today, CAD is a comprehensive and value-oriented solution for breast imaging facilities seeking to lead the pack.

On the CAD Horizon

Although the breast CAD market has been fairly uncrowded over the last several years, a few newcomers expect to jump into the market with CAD solutions in the next year.

Eastman Kodak expected FDA approval on its Kodak Mammography CAD System in November. Product Line Manager Terry Bogucki says the new system offers a small footprint that requires only desktop space and is focused on ease of use to minimize the impact on the technologist. The system includes a Vidar digitizer that can process 25 cases an hour. The initial offering addresses analog mammography; however, the company is working on a software upgrade to integrate digitally processed mammograms. Early clinical trials indicate that 39.4 percent of missed cancers could have been detected 14.8 months earlier with the Kodak system.

iCAD is eyeing the future as well and looking to add modalities to CAD. The company is collaborating with Walter Reed Army Medical Center and Windber Research Institute to develop and evaluate 3D CAD technology including CAD for breast ultrasound.
R2 is continuing to focus on the original challenge of CAD - improving outcomes - by supporting research to validate the technology. At the same time, the company is partnering with digital mammography vendors as new solutions hit the market. And because film-based mammography will be a reality for some time, the company will focus on better scanners to support higher throughput for analog mammography. Finally, the company is eyeing computer aided classification technology that would automatically classify suspicious lesions detected by CAD or a radiologist.

Siemens Medical Solutions is aiming to strengthen its position in the CAD market with the acquisition of Jerusalem-based CADVision Medical Technologies over the summer. Ingo Schmuecking, senior director of division marketing, says the company has a CAD solution for film and digital mammography in the advanced stage of development, but does not have regulatory approval yet. The company also is researching computer-aided classification tools.

VuComp, another newcomer, plans to submit its M-Vu CAD system for FDA approval by the middle of 2005. The system's algorithm is based on recognizing suspicious lesions based on concept rather than example and aims to address three problems associated with CAD, says company President Jeff Wehnes. According to Wehnes, "It's difficult to find masses smaller than one centimeter and identify architectural distortion with current CAD systems." Moreover, Wehnes says false positive rates are extremely high with current products. M-Vu captures important concepts and associated with breast lesions and places them in a mathematical framework. The first M-Vu system, which may hit the market in late 2005, will be designed for film-based mammography; a software upgrade for digital mammography will be available at later date.

The Ins & Outs of Digital Storage of CAD Images

Robert Lipman, MD, staff radiologist at Straub Clinic and Hospital (Honolulu, Hawaii), believes the ability to transfer and store
digitized mammograms in PACS is a key plus of CAD technology. The clinic relies on R2's DigitalNow for CAD and as a tool for
mammography storage. The mechanism is fairly simple. DigitalNow sends an MG class image to the clinic's Fujifilm Synapse PACS, and the PACS reads and understands the digitized image.

There are issues to consider with this option. For example, does the site store the CAD-marked images? Lipman says Straub Clinic started to store the CAD-marked images in PACS, but discontinued the practice for a number of reasons. He explains, "We were concerned about future comparisons. We want to compare the current to priors without marks, and next year, when we have full-field digital, we want to compare the priors with the correct current images. If we store the marked images, PACS might confuse the order."

There were other factors behind the decision to store straight digitized mammograms without CAD marks. CAD marks do require extra storage space. They also provide extra information that surgeons and patients don't need.

Another issue to consider is the number of mammography images to store in PACS. Michael Cloutier, manager of technical services for Catholic Medical Center (Manchester, N.H.), says the radiology department is discussing a plan for saving previous, analog scanned digitized images in PACS. He says, "Radiologists typically only go back one mammogram for reading, so storing more would take up expensive disk space." One common exemption to this pattern, however, is the case of a six-month follow-up where the radiologist requires the current images, the six-month follow up and the initial mammogram. In these cases, the hospital plans to store all three studies for future comparisons.

Lipman predicts that the mammography PACS archive will hold a mix of digital images and digitized film for a long time. He says, "Even after we implement digital, we'll continue to have film [with patients coming from other sites]." Consequently, Straub Clinic will continue to rely on DigitalNow as a scanning solution to minimize manual film-hanging. Looking into his crystal ball, Lipman makes a prediction. "We haven't yet dealt with this issue of comparing scanned mammograms to true digital images. There will probably be issues." Nonetheless, Lipman believes that the technical or human glitches that might occur are manageable with the benefits far outweighing the alternative processes for reading mammograms.