Patent ID: 7787596

Claim:
An x-ray absorption grid system comprising: at least two individual grids each produced by a lithography technique, said at least two individual grids being arranged atop one another in a direction of radiation propagation therethrough to form a grid combination, and each individual grid comprising a substrate with no gaps therein and a grid area on said substrate exhibiting a grid structure formed on said substrate with said substrate remaining beneath said grid structure, said grid structure comprising a plurality of radiation-absorbing grid webs and grid gaps in alternation; the substrate of each individual grid also comprising an outer region that extends outside of said grid area; the respective outer regions of the substrate of each of said at least two individual grids comprising toothed structures corresponding to one another at at least two points, said toothed structures being generated in the same lithography technique used to produce the grid structure; said toothed structures being located on the outer region of the substrate of each of said at least two individual grids at a defined position relative to the grid structure on that substrate, to produce a defined alignment of the respective individual grids relative to each other in said grid combination by engagement of the toothed structures of the respective individual grids atop one another; and the respective grid structures of said at least two individual grids, and said defined position and said defined alignment being structured relative to each other to set an interaction of said respective grid structures with said radiation propagating through said respective grid structures that produces a radiation beam exiting said grid combination that has beam characteristics for phase-contrast CT.