Technology update

Full field digital mammography has continued to develop. There is now a remarkable variety of different designs. One of the oldest (photo-stimulable phosphors) has received a new lease of life with the introduction of dual reading technology at a 50 m resolution. Systems using a selenium detector plate with a 70 m resolution are being introduced this year. Such systems have the advantage of converting X-ray energy directly to an electrical signal. A low dose system, which uses a scanning technique with a linear array of silicon detectors, has also been developed. Dual displays with 2000×2500 resolution are becoming standard. While such systems may be readily introduced into a symptomatic role, their use in screening remains problematic. All the digital systems can overcome the latitude limitations of the traditional film screen mammography, and appear to offer advantages in terms of image quality, particularly with better contrast resolution. The overall contrast can also be optimised for each image. The main limitations to the wider use of this technology remain the high start-up costs and the lack of proven clinical advantages.