Digital mammography features assure proper breast positioning

FOV and instant imaging minimize errors

Mammography depends as much on operator skill as technology. Poor positioning directly affects image quality, reducing the chance for breast cancer detection and accurate staging. Certain design features found on new digital mammography systems technology, however, can reduce the risk of error.

The SenoScan full-view digital mammography system from Fischer Imaging, for example, has a field-of-view 50% larger than film-based mammography. At 21 x 29 cm, SenoScan's FOV provides a full image of a breast of any size, reducing the amount of repositioning or image retaking in large-breasted women, said Al Palumbo, vice president of corporate communications and investor relations. Technologists face a bit of a learning curve to get up to speed on breast positioning using the SenoScan, but they usually are prepared to begin taking scans after Fischer's eight-hour training program.

Digital systems, such as the SenoScan and GE's Senographe 2000 D, allow images to be viewed immediately, thereby allowing operators to spot positioning errors quickly. Mammograms pop up within about a second on the Senographe and within five seconds on the SenoScan. Technologists can reshoot images that do not fully depict the pectoralis muscle, profile the nipple, or contain a sufficient amount of breast tissue.

The increased resolution on digital systems also makes mammography less susceptible to positioning errors. Standard resolution on the SenoScan is 10 line pairs/mm (14 lp/mm at high resolution), which in itself helps overcome positioning errors by making abnormalities easier to see, Palumbo said.

High dynamic ranges compensate for problems in positioning. GE's Tissue Equalization software automatically displays pertinent information. Its one-touch access physician keypad allows windowing through overlapping tissue, which reduces the number of retakes because of improperly positioned breast tissue.

While technology can solve some of the problems, nothing substitutes for old-fashioned book learning. GE Medical Systems holds a three-day onsite applications training course immediately after installation of its digital Senographe units. Additional training is provided by application specialists onsite and at GE's RiversEdge Education Center near Milwaukee. The company also provides a tip of the week to mammography technologists on its Web site, while sponsoring local and national seminars on breast positioning and new approaches in mammography. GE does not develop educational content but turns to Rita Heinlein, RT, a mammography consultant from the University of Baltimore, Clarksville, and the Greater Baltimore Medical Center. She is a recognized expert in breast positioning and mammography technologist training.