X-ray phase contrast imaging with fourier transform determination of grating displacement

An X-ray phase contrast imaging system comprising:

• an X-ray source;
• a detector configured to detect an X-ray irradiated from the X-ray source;
• a plurality of gratings disposed between the X-ray source and the detector, the plurality of gratings including a first grating for forming a self-image by being irradiated by the X-ray from the X-ray source and a second grating for forming an interference fringe with the self-image of the first grating by being irradiated by the X-ray that has passed through the first grating;
• and
• a grating positional displacement acquisition section configured to acquire a positional displacement of at least one of the plurality of gratings based on one or more peaks of a Fourier transform image obtained by Fourier transforming an interference fringe image detected by the detector.