DIGITAL RADIOGRAPHY - A REVIEW OF DETECTOR DESIGN

The last decade has seen a steady expansion in the use of digital imaging techniques in medicine. X-ray film radiographs may be digitised using a laser scanner or TV camera. Image intensifier-TV systems may readily be adapted to a digital role by capturing TV frames. Scintillators coupled to photomultiplier tubes or photodiodes have been used in line or spot scanning configurations where scatter rejection is high. A relatively recent development is the use of photostimulable phosphors, in which image information is extracted by laser scanning of the irradiated phosphor. Finally, imaging is an important part of radiotherapy treatment planning, where localisation and verification of X-ray treatment beams is required.