A comparison of image quality on 28 mammography X-ray sets in the UK.

Image quality has been assessed using three different phantoms on 28 mammographic X-ray units in the National Health Service Breast Screening Programme within the UK. The results show only relatively minor differences between different models of X-ray unit and between the 14 associated film processors, but more marked differences between different film-screen combinations. Medium screens give significantly lower image quality scores than fine screens from the same manufacturer. It is suggested that, to improve mammographic image quality, a change of screen type may bring greater benefit than a change of X-ray set model, as well as being much more cost effective.