Schröter Tobias J, Koch Frieder J, Meyer Pascal, Kunka Danays, Meiser Jan, Willer Konstantin, Gromann Lukas, De Marco Fabio, Herzen Julia, Noel Peter, Yaroshenko Andre, Hofmann Andreas, Pfeiffer Franz, Mohr Jürgen
Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
Chair of Biomedical Physics, Department of Physics and Institute of Medical Engineering, Technical University of Munich, 85748 Garching, Germany.
Rev Sci Instrum. 2017 Jan;88(1):015104. doi: 10.1063/1.4973632.
X-ray grating-based interferometry promises unique new diagnostic possibilities in medical imaging and materials analysis. To transfer this method from scientific laboratories or small-animal applications to clinical radiography applications, compact setups with a large field of view (FoV) are required. Currently the FoV is limited by the grating area, which is restricted due to the complex manufacturing process. One possibility to increase the FoV is tiling individual grating tiles to create one large area grating mounted on a carrier substrate. We investigate theoretically the accuracy needed for a tiling process in all degrees of freedom by applying a simulation approach. We show how the resulting precision requirements can be met using a custom-built frame for exact positioning. Precise alignment is achieved by comparing the fringe patterns of two neighboring grating tiles in a grating interferometer. With this method, the FoV can be extended to practically any desired length in one dimension. First results of a phase-contrast scanning setup with a full FoV of 384 mm × 24 mm show the suitability of this method.
基于X射线光栅的干涉测量技术有望在医学成像和材料分析领域带来独特的新诊断可能性。为了将这种方法从科学实验室或小动物应用转移到临床放射成像应用中，需要具有大视野（FoV）的紧凑型装置。目前，视野受到光栅面积的限制，由于制造工艺复杂，光栅面积受到限制。增加视野的一种可能性是将单个光栅片拼接起来，以创建一个安装在载体基板上的大面积光栅。我们通过应用模拟方法从理论上研究了拼接过程在所有自由度上所需的精度。我们展示了如何使用定制框架进行精确定位来满足由此产生的精度要求。通过比较光栅干涉仪中两个相邻光栅片的条纹图案来实现精确对准。使用这种方法，视野可以在一维上扩展到几乎任何所需的长度。全视野为384毫米×24毫米的相衬扫描装置的初步结果表明了该方法的适用性。
