A REAL-TIME, FLAT-PANEL, AMORPHOUS-SILICON, DIGITAL X-RAY IMAGER

As part of the development necessary for implementing a fully digital radiology department, the authors have investigated thin-film photodio des and transistors for use in new photoelectronic imaging devices. On e such device, a large-area, flat-panel, amorphous silicon imaging arr ay, has been developed and is currently being tested. The array has a format of 512 x 560 pixels, a pixel-to-pixel pitch of 450 mu m, and an area of 230 x 252 mm(2), making it the largest self-scanning, solid-s tate imaging array developed to date. The array is used in conjunction with an overlying x-ray converter. Although specifically designed for megavoltage imaging, the device can produce high-quality, low spatial resolution, diagnostic x-ray images. Qualitative comparisons of array images of anthropomorphic head, chest, and pelvic phantoms and a spat ial resolution pattern suggest that much of the information content of the film images at low spatial resolution is present in the correspon ding array images. Current trends in the development of large-area, fl at-panel imaging technology hold the promise of higher resolution arra ys in the near future.