Final answer:
The main disadvantage of digital mammography compared to screen film mammography is the higher cost. Digital mammography has better image quality but involves some level of radiation exposure, though optimized to be as low as possible.
Step-by-step explanation:
A disadvantage of digital mammography compared to screen film mammography is the higher cost associated with the equipment and the procedure. Digital mammography does offer benefits over traditional film, including improved image quality and easier image storage, but the initial expense can be a significant drawback for some healthcare facilities. Moreover, while digital mammography may use lower radiation doses compared to older film techniques, it is important to acknowledge that any form of mammography involves some level of radiation exposure. However, digital systems are designed to optimize the radiation dose to be as low as reasonably achievable while maintaining image quality for breast cancer detection.