| 摘要 |
An X-ray differential phase contrast imaging device (10) comprises an X-ray source (20) for generating an X-ray beam; a source grating (G0) for generating a coherent X-ray beam from a non-coherent X-ray source (20); a collimator (22) for splitting the coherent X-ray beam into a plurality of fan-shaped X-ray beams (28) for passing through an object (14); a phase grating (G1) for generating an interference pattern and an absorber grating (G2) for generating a Moiré pattern from the interference pattern arranged after the object (14); and a line detector (24) for detecting the Moiré pattern generated by the phase grating (G1) and the absorber grating (G2) from the fan-shaped X-ray beams (28) passing through the object (14). The X-ray source (20), source grating (G0), collimator (22), phase grating (G1), absorber grating (G2) and line detector (24) are fixed to a common gantry (12) and are movable with respect to the object (14), such that a number of interference pattern from different positions of the gantry are detectable for reconstructing a differential phase image of the object (14). At least one grating (G0, G1, G2) comprises, in an alternating manner, groups (36) of grating lines (34) and transparent areas (38). At least one grating (G0, G1, G2) is movable with respect to the gantry (12), such that in a first position of the grating (G1, G2) the fan-shaped X-ray beams (28) pass through the grating lines (34), and in a second position of the grating (G1, G2), the fan-shaped X-ray beams (28) pass through the transparent areas (38). |
