In this study, we designed a flat-panel digital X-ray imaging module based upon the
amorphous silicon (a-Si) technology and tested potential for medical imaging and nondestructive
testing. The module employs a commercially available a-Si photosensor array of a 143 μm x 143 μm
pixel size and a 42.9 cm x 42.9 cm active area, coupled with a CsI(Tl) scintillator of a 550 μm
thickness, and a readout IC board which can be accessed through our home made GUI software. The
experimental test was performed to evaluate the system response with exposure, modulation transfer
function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE).