Developing a quality control program for digital mammography: achievements so far and challenges to come

Detection of breast cancers with mammography is a challenging task. Images must be of high quality if cancers are to be found at the earliest possible time. This motivates the need for a quality assurance program. It has long been recognized that the performance of a complex imaging system such as mammography can drift over time and, therefore, quality control procedures must be in place to ensure that all components of the imaging chain are operating properly. While digital mammography overcomes many of the technical limitations of screen-film mammography, its performance can easily be diminished if it is carried out in a suboptimal manner. Routine quality control is equally important for digital mammography as it was for screen-film imaging. While the need to monitor film processing generally disappears when digital imaging is employed, there are new requirements for quality control related to the display workstation and imaging software. Furthermore, to aid in controlling radiation dose to the breast, it is important to establish a linkage between digital signal value and dose and to monitor signal levels over time. The availability of images in a digital format offers an opportunity to improve efficiency in that it permits automated testing to be performed.