There are both benefits and risks associated with most medical procedures. Medical imaging, especially imaging that exposes patients to ionizing radiation, is no exception. The goal of medical imaging is to provide the most useful medical information, at the lowest risk commensurate with providing that information. Mammography exposes the breast, one of the tissues most sensitive to ionizing radiation. Therefore, it is important to determine what level of image quality is required to permit appropriate medical decision making and consequently how much radiation is required.
In this Report the technical aspects of mammography are reviewed in detail and the principles of mammographic image quality are discussed with emphasis on the connection between image quality and absorbed dose to the breast tissue. The newly emerging modality, digital mammography, is also considered in some detail. While the importance of quality control (QC) for mammography is emphasized, there are several excellent publications on this topic so it is not covered extensively. Instead, what is provided is an outline of the aspects of imaging performance that should be tested upon installation of the equipment (acceptance testing) and periodically during its use (routine QC). As well, in the Appendices, some of the major QC programs in various countries or regions are described along with examples of test tools used in those programs.
This Report is intended for healthcare policy decision makers, radiologists, referring physicians, medical physicists and medical imaging radiographers (technologists). Mammography is widely used in many countries, with the potential of a large benefit in reducing mortality from breast cancer and facilitating the management of this disease. The principles discussed in this report should be helpful to the reader in helping to provide this benefit while reducing radiation-related risks to acceptable levels.