Development of Full Field Digital Mammography

Abstract

Screen-film mammography is well-established as a tool for screening and for diagnostic workup of suspicious lesions prior to biopsy. While mammography can be very accurate, its effectiveness can be limited because of several technical limitations in image formation and display, particularly when the breast contains a large proportion of fibroglandular tissue. The most significant limitation arises due to the use of photographic film as a means for image acquisition and display. The response of film is highly nonlinear, both for low and high exposures causing radiological contrast to be greatly reduced in regions of the image corresponding to both the most radio-lucent and the most radio-opaque parts of the breast. Bunch et al. [1] have shown that the signal to noise ratio (SNR) of information recorded by a mammographic screen-film system is low at both low and high exposure levels, and achieves its maximum at an intermediate exposure level, even though the inherent SNR of the image due to quantum statistics increases monotonically with exposure.