The present invention relates to calibration in X-ray phase contrast imaging. In order to remove the disturbance due to individual gain factors, a calibration filter grating (10) for a slit-scanning X-ray phase contrast imaging arrangement is provided that comprises a first plurality of filter segments (11) comprising a filter material (12) and a second plurality of opening segments (13). The filter segments and the opening segments are arranged alternating as a filter pattern (15). The filter material is made from a material with structural elements (14) comprising structural parameters in the micrometer region. The filter grating is movably arranged between an X-ray source grating (54) and an analyzer grating (60) of an interferometer unit in a slit-scanning system of a phase contrast imaging arrangement. The slit-scanning system is provided with a pre-collimator (55) comprising a plurality of bars (57) and slits (59). The filter pattern is aligned with the pre-collimator pattern (61).

The present invention relates to a method and apparatus for X-ray phase contrast imaging. The method comprises the following steps: from the measured phase gradient and overall attenuation information, an electron density is computed; the contribution p.sub.c of the Compton scattering to the overall attenuation is estimated from the electron density; the contribution pp of the photo-electric absorption to the overall attenuation is estimated from the overall attenuation and the contribution p.sub.c; the values p.sub.c and p.sub.p are used to reconstruct a Compton image and a photo-electric image; by linear combination of these two images, a monochromatic image at a desired energy is obtained.

Provided is a radiation phase-contrast imaging device capable of assuredly detecting a self-image and precisely imaging the internal structure of an object. According to the configuration of the present invention, the longitudinal direction of a detection surface of a flat panel detector is inclined with respect to the extending direction of an absorber in a phase grating. This causes variations in the position (phase) of a projected stripe pattern of a self-image at different positions on the detection surface. This is therefore expected to produce the same effects as those obtainable when a plurality of self-images are obtained by performing imaging a plurality of times in such a manner that the position of the projected self-images on the detection surface varies. This alone, however, results in a single self-image phase for a specific region of the object. Therefore, according to the present invention, it is configured such that imaging is performed while changing the relative position of the imaging system and the object.

A Talbot imaging apparatus includes a radiation source, a plurality of gratings, a capturing control unit, a radiation detector, a setting unit and an irradiation control unit. The radiation source irradiates radiation. The capturing control unit relatively shifts the plurality of gratings and performs control of capturing a plurality of Moire images of a subject to generate a reconstructed image. The radiation detector acquires a captured Moire image. The setting unit sets a capturing condition for capturing a second and further Moire images by making a capturing result of a first Moire image be a reference, or sets a capturing condition for the plurality of Moire images by making another Moire image captured before capturing the plurality of Moire images be a reference. The irradiation control unit controls irradiation of radiation from the radiation source based on the capturing condition set by the setting unit.

The invention relates to a system and a method for active grating position tracking in X-ray differential phase contrast imaging and dark-field imaging. The alignment of at least one grating positioned in an X-ray imaging device is measured by illuminating a reflection area located on the grating with a light beam, and detecting a reflection pattern of the light beam reflected by the reflection area. The reflection pattern is compared with a reference pattern corresponding to an alignment optimized for X-ray differential phase contrast imaging, and the X-ray imaging device is controlled upon the comparison of the reflection pattern and the reference pattern.

A radiation phase change detection method includes: arranging a two-dimensional optical image pickup element, which includes a scintillator, so that, when a period of a self-image generated through a phase grating is defined as D.sub.1, and a pixel pitch of the two-dimensional optical image pickup element is defined as D.sub.2=kD.sub.1, k falls in a range of 1/2<k≦3/2, and so that interference fringes formed by D.sub.1 and D.sub.2 depending on a relationship in arrangement of the two-dimensional optical image pickup element with respect to the self-image have a period of 2 times D.sub.2 or more and 100 times D.sub.2 or less; acquiring images of the interference fringes before and after insertion of an object; and outputting an image on a phase change of the radiation caused by at least the object.

The invention relates to gratings for X-ray differential phase-contrast imaging, a focus detector arrangement and X-ray system for generating phase-contrast images of an object and a method of phase-contrast imaging for examining an object of interest. In order to provide gratings with a high aspect ratio but low costs, a grating for X-ray differential phase-contrast imaging is proposed, comprising a first sub-grating (112), and at least a second sub-grating (114; 116; 118), wherein the sub-gratings each comprise a body structure (120) with bars (122) and gaps (124) being arranged periodically with a pitch (a), wherein the sub-gratings (112; 114; 116; 118) are arranged consecutively in the direction of the X-ray beam, and wherein the sub-gratings (112; 114; 116; 118) are positioned displaced to each other perpendicularly to the X-ray beam.

Systems and methods for X-ray phase-contrast imaging (PCI) are provided. A quasi-periodic phase grating can be positioned between an object being imaged and a detector. An analyzer grating can be disposed between the phase grating and the detector. Second-order approximation models for X-ray phase retrieval using paraxial Fresnel-Kirchhoff diffraction theory are also provided. An iterative method can be used to reconstruct a phase-contrast image or a dark-field image.

A radiation capturing system includes the following. A radiation source, a plurality of gratings, and a radiation detector, are provided aligned in a radiation irradiating axis direction. A Talbot interferometer or a Talbot-Lau interferometer captures a moire fringe image for generating a reconstructed image. A low visibility capturing unit performs capturing of the moire fringe image with visibility of a moire fringe reduced more than in capturing of the moire fringe image for generating the reconstructed image. A generating unit generates an absorptive image based on the moire fringe image captured by the low visibility capturing unit.

According to a method for manufacturing a metal grating structure of the present invention, in filling a concave portion formed in a silicon substrate (30), for instance, a slit groove (SD) with metal by an electroforming method, an insulating layer (34) is formed in advance on an inner surface of the slit groove (SD) as an example of the concave portion by a thermal oxidation method. Accordingly, the metal grating structure manufacturing method is advantageous in finely forming metal parts of the grating structure. A metal grating structure of the present invention is manufactured by the above manufacturing method, and an X-ray imaging device of the present invention is incorporated with the metal grating structure.