APPARATUS FOR X-RAY DARK-FIELD AND/OR X-RAY PHASE CONTRAST IMAGING USING STEPPING AND MOIRÉ IMAGING

Disclosed is an apparatus for X-ray dark-field and/or X-ray phase-contrast imaging. The apparatus has an imaging system, which includes a first and a second X-ray optical grating and an X-ray sensitive image detector having an ordered array of X-ray sensitive pixels. When no object is present, the first grating generates a fringe pattern in an entrance plane of the second grating. The second grating is configured to generate a Moire pattern from the fringe pattern so that the Moire pattern has a pitch which is less than 20 times a pixel pitch of the pixels of the X-ray sensitive image detector. The imaging system further comprises a controller, which is configured to control a relative movement between the second grating and the fringe pattern to acquire a Moiré-image at each of a plurality of different relative image acquisition positions when the object is present.