GRATING FOR PHASE CONTRAST IMAGING

摘要

The present invention relates to foil-gratings for X-ray differential phase-contrast imaging, a detector arrangement and an X-ray imaging system for generating phase-contrast images of an object and a method of producing a foil-grating. In order to provide gratings with a high aspect ratio, a foil-grating (40) for X-ray differential phase-contrast imaging is provided with a first foil (42) of X-ray absorbing material; and at least a second foil (44) of X-ray absorbing material. The at least two foils each comprise a plurality of X-ray absorbing stripes spaced from each other by X-ray transparent apertures, wherein the first foil comprises a first plurality (46) of first stripes (48) with a first width w1 (50), and a first plurality (52) of first apertures (54) with a first opening width wO1 (56) arranged periodically with a first pitch p1 (58), and wherein the second foil comprises a second plurality (60) of second stripes (62) with a second width w2 (64), and a second plurality (66) of second apertures (68) with a second opening width wO2 (70) arranged periodically with a second pitch p2 (72). The at least two foils are arranged displaced to each other such that the second stripes are positioned in front of the first apertures such that for the passage of X-ray radiation a plurality (74) of resulting slits (76) is provided with a resulting slit width WR (78) that is smaller than the first wO1 and the second opening width wO2. The at least two foils are fixedly attached to each other.