Patent Number: 
Section: claims

1. A grating interferometer system for obtaining absorption, differential phase contrast (DPC) and dark-field data from quantitative X-ray images from a sample, the grating interferometer system comprising:an X-ray source;gratings including one of:a phase grating and an analyzer grating; ora source grating, said phase grating and said analyzer grating;a position-sensitive detector;means for recording images of said position-sensitive detector;means for evaluating intensities for each pixel in a series of the quantitative X-ray images, in order to identify characteristics of an object for each individual pixel as at least one of an absorption-dominated pixel, a DPC-dominated pixel, and an X-ray dark-field dominated pixel;means to tilt either said phase grating or said analyzer grating by a predetermined angle; andmeans to move the sample, said x-ray source, or said gratings and said position-sensitive detector to perform a scanning of a probe; andwherein for near-field-regime operation, a distance between said gratings is chosen freely within the near-field-regime, and a Talbot-regime is chosen according to:            D              n        ,        sph              =                            L          ·                      D            n                                    L          -                      D            n                              =                                    L            ·            n            ·                                          p                1                2                            /              2                                ⁢                                          ⁢                      η            2                    ⁢          λ                          L          -                                    n              ·                                                p                  1                  2                                /                2                                      ⁢                                                  ⁢                          η              2                        ⁢            λ                                    where    ⁢                                    n        =        1            ,      3      ,              5        ⁢                                  ⁢        …            ⁢                          ,      and        ⁢                      η    =          {                                    1                                                                                          ⁢                                                if                  ⁢                                                                          ⁢                  the                  ⁢                                                                          ⁢                  phase                  ⁢                                                                          ⁢                  shift                  ⁢                                                                          ⁢                  of                  ⁢                                                                          ⁢                                      G                    1                                    ⁢                                                                          ⁢                  is                  ⁢                                                                          ⁢                                      (                                                                  2                        ⁢                        l                                            -                      1                                        )                                    ⁢                                      π                    2                                                  ,                                                      p                    2                                    =                                                                                    L                        +                                                  D                                                      n                            ,                            sph                                                                                              L                                        ⁢                                          p                      1                                                                                                                                2                                                              if                ⁢                                                                  ⁢                the                ⁢                                                                  ⁢                phase                ⁢                                                                  ⁢                shift                ⁢                                                                  ⁢                of                ⁢                                                                  ⁢                                  G                  1                                ⁢                                                                  ⁢                is                ⁢                                                                  ⁢                                  (                                                            2                      ⁢                      l                                        -                    1                                    )                                ⁢                                  π                  2                                            ,                                                p                  2                                =                                                      L                    +                                          D                                              n                        ,                        sph                                                                              L                                                                        where l=1, 2, 3 . . . , Dn is an odd fractional Talbot distance when a parallel X-ray beam is used, G1 is said phase grating, Dn,sph is when a fan or cone X-ray beam is used and L is a distance between said source grating and said phase grating. 2. The system according to claim 1, wherein said phase grating is a line grating, an absorption grating or a phase grating that is a low-absorption grating but generating a considerable X-ray phase shift and of Π or odd multiples thereof. 3. The system according to claim 1, wherein said analyzer grating is a line grating having a high X-ray absorption contrast with its period being a same as that of a self-image of said phase grating, wherein said analyzer grating is placed closely in front of said position-sensitive detector with its lines parallel to those of said phase grating, before tilting said phase grating or said analyzer grating. 4. The system according to claim 1, wherein said position-sensitive detector is a line sensitive detector. 5. A method to retrieve absorption, differential phase contrast (DPC) and dark field signals from a Moire fringe pattern obtained by detuning a grating interferometer system having an X-ray source, a phase grating, an analyzer grating and a line sensitive detector, which comprises the steps of:producing the Moire fringe pattern of a desired period by tilting one of the phase grating or the analyzer grating by a predetermined angle; andcalculating a tilting angle using:a period P2 of the analyzer grating;a number n of detector lines;a number m of the periods P2 that are to be covered;a separation D between the detector lines of the line sensitive detector;and employing formulas:            δ      x        =          m      ⁢                        p          2                n                  θ    =          arc      ⁢                          ⁢              tan        ⁡                  (                                    δ              x                        D                    )                    where θ is the tilting angle; andscanning either a sample or the grating interferometer system along the Moire fringe pattern. 6. The method according to claim 5, which further comprises using reference and sample data acquired with the grating interferometer system to retrieve the absorption, the DPC and the dark-field signals by Fourier Component analysis. 7. The method according to claim 5, wherein:the grating interferometer system has the phase grating and the analyzer grating, and one of the phase grating and the analyzer grating is tilted; orthe grating interferometer system has a source grating, the phase grating and the analyzer grating, and wherein:only the phase grating is tilted; oronly the analyzer grating is tilted; ora pair of the source grating and the phase grating is tilted; ora pair of the phase grating and the analyzer grating is tilted. 8. The method according to claim 5, wherein compatible with radiography, tomosynthesis and computed tomography, either the sample or the grating interferometer system is rotated to acquire multiples views.