U. tests digital mammogram

Researchers at the University's Medical Center are testing a new computer imaging system that could lead to earlier and more accurate detections of female breast cancer. The American Cancer Society recommends that women as young as 40 receive annual or biannual mammograms. But problems with current mammography technology often lead to misdiagnoses. More than 180,000 new cases of breast cancer will be diagnosed this year, according to the ACS. The disease is expected to kill almost 45,000 women in 1997. The new digital technology captures higher resolution images of the breast than conventional a mammogram. The improved resolution allows radiologists to zoom in and out of images, highlighting questionable regions in the breast to examine them more closely. "You can hone in on certain aspects of the breast," explained Hospital of the University of Pennsylvania radiologist Emily Conant, who has been using the new system since the beginning of last month. Conant, who heads HUP's Breast Imaging Section, added that "the real question here is what is the necessary resolution for diagnosis." Conventional mammograms provide images with resolutions of up to 50 millimeters. Digital mammography increases resolution to between 50 and 100 microns, a high level of detail beyond the capacities of most computer monitors. The new technology uses a filmless system that stores images on a computer or magnetic tape, allowing them to be sent over the Internet. Digital storage also lessens the chance of losing the images and having to replace them, which would require patients to go through another dose of radiation. "Patients are very comfortable with the machine because it doesn't look any different," Conant said. "It's really the same technique that they're used to." The procedure involves placing the breast on a small platform. The breast is compressed, so less radiation is required to reach its center. Then, a camera rotates around the platform, taking several pictures at different angles. The difference in digital mammography is a small, black box placed underneath the platform, which generates the higher resolution images. Future applications of digital mammography could include three-dimensional renderings of the breast and computer-aided diagnoses. While the initial images obtained with the new technology appear to be more accurate than those from conventional mammograms, Conant stressed that the technology is still in the clinical trial stage. "Within five years, this will be the state of the art at bigger institutions," she said. "It will be easier to install as the technology becomes less expensive." But before the device gains widespread use, it is important "to make sure that it is at least as good as film screen mammography at detecting breast cancer," according to Harvard Radiologist Carol Hulka, who worked in Massachussettes General Hospital's Radiology Department when it conducted early clinical trials in digital mammography. Conant added that women should begin frequent self-examinations in late teens and early twenties, since mammography has not yet proved itself as an absolute diagnosis.