Amorphous silicon flat-panel detection technology -- indirect imaging technology
It is composed of CsI scintillator layer, photodiode and TFT.
The CsI scintillator layer absorbs incident X-ray radiation and coverts it to visible light. The visible light in turn converted by photodiodes to electric charges, which are stored on the photodiodes themselves. The charges quantities represent the signals and are read out by switching TFT to form a digital image. CsI is very efficient to convert X-ray image, thus it can produce very sensitive detector, also with needle-like structure can reduce the light scattering to maintain high spatial resolution.