According to Sughra Raza, MD, of Brigham and Women's Hospital in Boston, MA, who conducted the study, both types of mammography use X-rays to create the image of the breast, but the difference between the two is in how the image is recorded. In digital mammography, it is digitally recorded and stored, whereas with conventional mammography a hardcopy of the image is printed. "With digital mammography, we have the advantages of being able to manipulate the image for optimal visualization and magnification. Archiving and storage of digital mammography also requires less physical space than conventional films," said Dr. Raza.
Call-backs occur for either technical or diagnostic reasons, according to Dr. Raza. "If the images do not meet standard quality requirements or if either better or additional views are required for complete interpretation of a finding, we will call the patient back for more imaging," said Dr. Raza.
The screening mammography center at Dr. Raza's institution recently changed over from conventional to digital mammography. For the study, Dr. Raza compared mammograms from six-month time periods prior to and after that switch, and all interpreted by the same radiologists. She found that of the 6,189 conventional film screen mammograms, 274 patients were called back for a 4.4% call back rate; of the 6,792 digital mammograms, 216 were called back for a 3.2% call back rate. "This data suggests that use of digital mammography can reduce the call back rate by 1.2%, or 12 per thousand screening mammography patients. At our institution this would translate to roughly 160 women over a full year," said Dr. Raza.
"Calling a patient back is the cause of much anxiety for the patient, as well as cost to the patient in possible time away from work, child care and general hassle. It also incurs all the monetary costs of an additional examination and perhaps even an ultrasound examination. Decreasing call backs may lead to a substantial reduction of all these costs," said Dr. Raza.
Dr. Raza will present the full results of the study on May 17 during the American Roentgen Ray Society Annual Meeting in New Orleans, LA.
The American Roentgen Ray Society (ARRS) was founded in 1900 and is the oldest radiology society in the U.S. Radiologists from all over the world attend the ARRS Annual Meeting to take part in instructional courses, scientific paper presentations, symposiums, new issues forums and scientific and commercial exhibits related to the field of radiology. The ARRS is named after Wilhelm Röentgen, who discovered the x-ray in 1895. For more information, visit www.arrs.org.