Detective quantum efficiency of an x-ray image intensifier chain as a benchmark for amorphous silicon flat-panal detectors

Abstract

Amorphous silicon flat panel x-ray detectors (A-Si FXD) are expected eventually to replace traditional x-ray image intensifier systems (XRII) in medical radiography in the long term. The advantages of FXD's are their large detection area, no distortion, no sensitivity to magnetic fields, low weight and compactness. However, they do not provide the high sensitivity of specific optimized systems based on image intensifiers, which approach the sensitivity of single x-ray photon counting in an appropriate configuration whereas the noise equivalent number of photons for an a-Si imager is typically several photons at medical energies. That is, the detective quantum efficiency of an XRII at low dose is expected to be higher.