System for obtaining quantitative x-ray images using Hilbert transform on imaged fringes
摘要
The invention is concerning grating based X-ray phase contrast imaging. More specifically, the invention is a single shot, single grating (phase) method capable of obtaining differential phase contrast, absorption and scattering images of a sample simultaneously. This is achieved by utilizing high resolution which is provided by single photon sensitivity of charge integrating detectors (with pixel sizes in the 10-50 µ m range) or like. The high resolution (approx. 1 µ m) allows the recording of the interference fringe (Talbot effect) that is created by a phase or absorption grating 1D or 2D. Once the fringe has been recorded a phase retrieval method based on the Hilbert Transform (HT) was developed in order to retrieve the three aforementioned images. The phase retrieval method provides average phase values (also absorption and scattering) for each pixel or area of the detector.