Analysis Of Flat Fields In Edge Illumination Phase Contrast Imaging

One of the most commonly used correction methods in X-ray imaging is flat field correction, which corrects for systematic inconsistencies, such as differences in detector pixel response. In conventional X-ray imaging, flat fields are acquired by exposing the detector without any object in the X-ray beam. However, in edge illumination X-ray CT, which is an emerging phase contrast imaging technique, two masks are used to measure the refraction of the X-rays. These masks remain in place while the flat fields are acquired and thus influence the intensity of the flat fields. This influence is studied theoretically and validated experimentally using Monte Carlo simulations of an edge illumination experiment in GATE.