MAMMOGRAPHY

The wait for full-field digital systems continues as vendors tout biopsy systems and computer-aided diagnosis

Mammography inches forward with digital units

Full-field systems promise to eliminate retakes, aid image manipulation, and possibly improve image quality. But vendors will have to prove that the additional benefits of the systems justify their cost. And if reimbursement makes or breaks a technology's success, digital has a formidable challenge: Routine breast exams are reimbursed at rates ranging from $35 to $75. Whether this is sufficient to cover the costs of the new technology remains to be seen.

An emerging mammography technology that will be featured on the RSNA floor is computer-aided diagnosis, with products under development by companies such as Qualia, R2 Technology, and Scanis. CAD workstations can provide a radiologist with the equivalent of a second reader, and use software algorithms to interpret images and mark suspicious areas for further review. To date, R2 Technology is the only company to have received clearance for its system, the ImageChecker workstation.

Mammography technologies that are not based on x-ray film will also be on display. Companies such as IDSI and TransScan are developing alternative technologies to image the breast using infrared laser light or electrical impulses. These systems will be shown as works-in-progress.

WHAT TO LOOK FOR

Fischer. Fischer plans to showcase a surgical version of its breast biopsy table called Mammotest Plus S, as well as an ultrasound-guided gantry that attaches to the unit. Also highlighted in Fischer's booth will be its full-field digital mammography system, SenoScan. Fischer expected to have a 510(k) application on file for SenoScan with the FDA before the
conference.

GE. GE will show as a work-in-progress its ongoing development of a digital mammography system using flat-panel amorphous silicon detectors. GE will highlight the improved image quality of the detector relative to conventional mammography systems, as well as the new clinical applications possible with the device, such as telemammography. The company will also show its digital spot mammography device, SenoVision, which is based on charge-coupled device (CCD) technology.

Imaging Diagnostic Systems. IDSI will bring the latest incarnation of its CT laser mammography (CTLM) system, a work-in-progress unit that uses infrared laser light to image breast tissue. IDSI has refined CTLM's laser and reconstruction algorithms, as well as its scanning table. The company has begun submitting data to the FDA as its clinical trials progress.

Instrumentarium. Instrumentarium plans to highlight its Delta16 TACT (tuned-aperture computed tomography), a digital spot and stereotactic biopsy system that collects images from different angles of the breast and converts them into slices to develop a 3-D image. The company expects to apply for 510(k) clearance by conference time. Instrumentarium will also present its work-in-progress Delta DX, a full-field digital mammography system that uses flat panels.

Planmed. Planmed will bring two upgrades to its Sophie Classic mammography system. The company has incorporated a high-speed, high-output x-ray tube into the system, and has developed a Sophie Classic Twincomp model with a bi-phasic paddle that compresses tissue toward the chest wall, maximizing the unit's ability to capture tissue on film. While Twincomp has been cleared by the FDA, Planmed's new x-ray tubes are yet to be cleared.

Qualia. Qualia will introduce a prototype of its Second Look CAD workstation, which is based on neural network software that marks microcalcifications and suspicious masses in mammography images. The company expects to begin clinical trials before the end of the year, and has begun meeting with the FDA to discuss submission of a premarket approval (PMA) application. Qualia will also introduce a prototype of what it calls a network-based, region-of-concern server it is developing to integrate with digital mammography systems.

R2 Technology. With a PMA in hand, R2 will emphasize its ImageChecker CAD mammography workstation, displayed at last year's RSNA conference as a work-in-progress. The system uses pattern recognition algorithms to identify possible breast abnormalities, and neural network technology to distinguish real lesions from normal tissue. R2 signed an exclusive agreement with GE in May under which the multimodality vendor will distribute ImageChecker for use with its full-field digital systems, pending FDA clearance.

Scanis. On display in the Scanis booth will be Mammex TR, a CAD workstation the company developed in conjunction with TRW Center for Medical Imaging Analysis. Mammex TR uses a rule-based algorithm system rather than neural networks to locate and highlight suspicious areas. Scanis plans to begin preparing for an FDA regulatory submission early next year, and expects to offer the unit outside the U.S. by conference time.

Siemens. Siemens' special products division plans to bring its work-in-progress Mammomat full-field digital system and workstation, and expects to begin clinical trials of the system in 1999. The company will also display its Opdima digital spot option, cleared by the FDA in mid-1997. Siemens will also present Biopsys' Mammotome biopsy technology as an option to Siemens' upright system. Mammotome will enable users to do both breast imaging workup screening and biopsy.

TransScan. TransScan received a recommendation for premarket approval in August for its TransSpectral Impedance Scanning device, TS-2000. The hand-held system transmits low-voltage electrical signals into body tissue, measuring the changes in the signal to give information about the tissue's quality. The company expects to receive FDA clearance this year. TransScan will also present TS-3000, a next-generation scanner that measures electrical impedance using plates similar to those used in mammography, and therefore produces images comparable to mammography images.

Trex. Highlighted in the Trex mammography booth will be the company's full-field digital mammography unit, Trex Digital Mammography System (TDMS), which debuted at last year's RSNA meeting and is pending 510(k) clearance. Trex's Bennett X-Ray division will display two next-generation mammography Systems, Contour 2000 and Profile 2000, as well as StereoView and Digital StereoView, stereotactic units compatible with sampling devices such as Biopsys' Mammotome.

MS. MADDEN YEE is an assistant editor of Diagnostic Imaging Scan newsletter.