Digital Mammography Increases Accuracy
The Imaging Center for Women converted from analog mammography to digital mammography in October 2007. Since then, Radiologic Associates of Fredericksburg has reported the enhanced ability to visualize low-density calcifications in high-density breasts. Mammogram films of high-density breasts are more difficult to read because dense breasts have less fat than glandular and connective tissue.
“Low-density calcifications can look like four or five tiny speckles of salt when reading a mammogram. The quality of digital mammography makes them much easier to find in dense breast tissue,” said Aye Min, MD, of Radiologic Associates of Fredericksburg, one of the center’s eight dedicated radiologists.
The Imaging Center for Women is a partnership between RAF and MediCorp. Donald Allen, MD, RAF radiologist and medical director of the center, said the facility is among an estimated 49 percent nationwide that have converted to digital mammography. Conversion is a relatively expensive process, but one that the center was poised to make after studies confirmed the efficacy of digital mammography.
“We felt the quality of images was so much greater and interpretation was so much easier with digital mammography. You can see calcifications better and the images have much more contrast and therefore detail. Studies have shown that digital mammography is particularly effective for imaging women who are younger than 50, and those with dense breasts,” according to Dr. Allen.
A landmark study published in a special online edition of the New England Journal of Medicine on Sept. 16, 2005 concluded that the “overall diagnostic accuracy of digital and film mammography as a means of screening for breast cancer is similar, but digital mammography is more accurate in women under the age of 50 years, women with radiographically dense breasts, and premenopausal or perimenopausal women.” The study, known as the American College of Radiology Imaging Network Digital Mammographic Imaging Screening Trial (DMIST), estimated that digital mammography was up to 28 percent more effective at detecting breast cancer in these populations. Results were based on evaluations of more than 42,000 asymptomatic women who received both film and digital examinations at 33 sites in North America.
Digital mammography also simplifies the process of sharing results with referring physicians and comparing mammograms over time, Dr. Allen noted. In addition, digital mammography enables digital storage and transfer capabilities that are becoming increasingly important in the healthcare industry.
Experience and Training
Radiologists at The Imaging Center for Women read more than 30,000 mammograms annually, making it one of the busiest facilities in the state. To prepare for the conversion to digital mammography, Drs. Allen and Min visited the facility of the lead researcher for DMIST, Etta Pisano, MD, of the University of North Carolina, Chapel Hill. Radiologists and technicians at The Imaging Center for Women also received special training through continuing medical education to meet the standards of the American College of Radiology.
Pictured above is Comparison of digital and film mammogram. Questionable area, just below the nipple, is more easily visible in the digital image.