The present invention relates to X-ray imaging. In order to reduce X-ray dose exposure during X-ray image acquisition, an X-ray detector is provided that is suitable for phase contrast and/or dark-field imaging. The X-ray detector comprises a scintillator layer (12) and a photodiode layer (14). The scintillator layer is configured to convert incident X- ray radiation (16) modulated by a phase grating structure (18) into light to be detected by the photodiode layer. The scintillator layer comprises an array of scintillator channels (20) periodically arranged with a pitch (22) forming an analyzer grating structure. The scintillator layer and the photodiode layer form a first detector layer (24) comprising a matrix of pixels (26). Each pixel comprises an array of photodiodes (28), each photodiode forming a sub- pixel (30). Adjacent sub-pixels during operation receive signals having mutually shifted phases. The sub-pixels that during operation receive signals having mutually identical phase form a phase group per pixel. The signals received by the sub-pixels within the same phase group per pixel during operation are combined to provide one phase group signal (32). The phase group signals of different phase groups during operation are obtained in one image acquisition. In an example, the pitch of the scintillator channels is detuned by applying a correcting factor c to a fringe period (Pfringe) of a periodic interference pattern (35) created by the phase grating structure, wherein 0<； c <；2.La présente invention concerne l'imagerie à rayons X. Un détecteur de rayons X convenant à l'imagerie à contraste de phase et/ou sur fond noir permet de réduire l'exposition à la dose de rayons X lors de l'acquisition d'images de rayons X. Le détecteur de rayons X comprend une couche de scintillateur (12) et une couche de photodiode (14). La couche de scintillateur est conçue pour convertir un rayonnement de rayons X incidents (16) modulé par une structure de réseau de phase (18)
