What is phase contrast technology?
Materials with poor X-ray absorption can be challenging for conventional X-ray imaging devices. However, objects visualized by propagation-based X-ray imaging will exhibit absorption contrast as well as phase contrast information. The phase contrast is a direct result of free-space propagation of the X-ray beam, transforming X-ray phase changes at the object plane into X-ray intensity variations in the image plane. Propagation-based phase contrast X-ray imaging can result in increased contrast at object boundaries for better detectability of materials with poor X-ray absorption.
The hybrid a-Se/CMOS detector uses an a-Se photoconductor with high intrinsic spatial resolution for direct conversion of X-ray photons to electric charge. The electronic signal is then read out by a low noise CMOS active pixel sensor (APS). Without the need to first convert X-ray photons to visible light, as in indirect scintillator-based approaches, thinning of the conversion layer to minimize optical scatter is not necessary.
The direct conversion approach allows a thick conversion layer and operation at 100% fill factor for high DQE. At 35 keV, BrillianSe™ has a market leading combination of high DQE (40% at 10 cycles/mm) and a small point-spread function (PSF) (1.1 pixel). This facilitates imaging for low flux applications such as X-ray diffraction, dose sensitive protein crystallography or throughput-limited imaging of materials with and without phase-contrast.
Learn more: inCiTe Technical Note
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Comparing conventional and phase contrast imaging
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