Optimization of phase contrast imaging using hard x rays
Optimization of phase contrast imaging using hard x rays
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DOI：
10.1063/1.1960797
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发表时间：
2005-07-01
影响因子：
1.6
通讯作者：
Schlenker, M
中科院分区：
文献类型：
--
作者：
Zabler, S;Cloetens, P;Schlenker, M
X射线照相术和断层摄影术是医学以及生命科学和材料科学中的重要工具。不久前，一种称为基于简单传播的同轴全息术的方法成为可能，使用部分相干同步加速器光束，如欧洲同步辐射设施（ESRF）提供的光束。Cloetens [Appl.Phys.Lett 75，2912（1999）]的理论和实验工作已经表明，从在不同样品到检测器距离处拍摄的一组射线照片中定量检索光学相位是可行的。从数学上讲，我们正在处理一个基于线性化的直接方法，以解决逆非线性问题。相位恢复可以与经典的层析成像相结合，以获得物体电子密度的三维表示（全息层析成像）。为了优化数值相位恢复过程的图像对比度，我们进行了计算，从而优化选择的值和数量的样品到检测器的距离以及光子能量。这些结果随后通过ESRF长光束线ID19上的实验得到证实。(c)2005年美国物理学会。
X ray radiography and tomography are important tools in medicine as well as in life science and materials science. Not long ago an approach called in-line holography based on simple propagation became possible using partially coherent synchrotron beams like the ones available at the European Synchrotron Radiation Facility (ESRF). Theoretical and experimental work by Cloetens [Appl. Phys. Lett 75, 2912 (1999)] have shown that quantitative retrieval of the optical phase, from a set of radiographs taken at different sample-to-detector distances, is feasible. Mathematically speaking we are dealing with a direct method based on linearization in order to solve an inverse nonlinear problem. The phase retrieval can be combined with classical tomography in order to obtain a three-dimensional representation of the object's electron density (holotomography). In order to optimize the image contrast for the numerical phase retrieval process, we have carried out calculations resulting in an optimized choice of value and number of the sample-to-detector distances as well as of the photon energy. These results were then confirmed by experiments on the ESRF long beamline ID19. (c) 2005 American Institute of Physics.