AAPM/RSNA physics tutorial for residents: technological and psychophysical considerations for digital mammographic...

Digital mammography is gradually replacing screen-film analog mammography, a transition driven by a desire to improve the efficiency and possibly the quality of the interpretation of mammograms. Digital mammography involves the use of electronic display devices to display the mammograms. Currently, two electronic technologies are used to display digital mammograms: the cathode-ray tube (CRT) and liquid crystal display (LCD). CRT and LCD devices have imaging characteristics markedly different from those of transilluminated film, which has conventionally been used to display analog mammograms. Consequently, the transition to digital mammography necessitates consideration of a number of psychophysical factors pertaining to effective display of mammograms. Some of these factors are related to specific performance characteristics of the display devices, whereas others are related to inherent characteristics of the human visual system. The main psychophysical factors that affect the interpretation of medical images are contrast, resolution, and noise. Optimal display of mammograms is achieved by taking these factors into consideration and by using time-efficient, intuitive, and reader-specific user interfaces. Because display devices are susceptible to variations in hardware and calibration and to degradation over time, acceptance testing and quality control testing are necessary to maintain an adequate level of display quality.