US Patent 9952163 Coded-aperture X-ray imaging

A method of X-ray imaging includes passing an X-ray beam through a pre-sample mask 8 with a plurality of apertures 32, through a sample 10, and then through a detector mask 6 with aligned apertures 34. The beams are detected. The detector mask 6 and pre-sample mask 8 are moved with respect to one another to identify the position of maximum intensity and then moved to two further positions on equal and opposite spacings on either side of the maximum. Images are acquired and a transmission image, refraction image and scattering image calculated.