Applications of a non-interferometric x-ray phase contrast imaging method with both synchrotron and conventional sources
Applications of a non-interferometric x-ray phase contrast imaging method with both synchrotron and conventional sources
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DOI：
10.1088/1748-0221/8/05/c05008
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发表时间：
2013-05
影响因子：
1.3
通讯作者：
M. Endrizzi;P. Diemoz;P. Munro;C. Hagen;M. Szafraniec;T. P. Millard;C. Zapata;R. Speller;A. Olivo
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文献类型：
--
作者：
M. Endrizzi;P. Diemoz;P. Munro;C. Hagen;M. Szafraniec;T. P. Millard;C. Zapata;R. Speller;A. Olivo
我们发展了一种完全非相干、非干涉的X射线相衬成像(XPCI)方法。这是基于90年代末意大利Elettra同步加速器开发的边缘照明(EI)概念。该方法随后适用于由传统光源产生的发散光束，方法是通过适当的掩模为每条探测器线复制发散光束。该方法用简化的光线跟踪和更严格的波动光学方法进行了模拟，两种情况下都与实验结果很好地吻合。波动光学模型能够评估这些方法的一致性要求，表明它们至少比其他方法宽松一个数量级，而不会对相位敏感度产生负面影响。我们的掩模具有大间距(例如，比光栅干涉法大50倍)，允许通过标准光刻、可扩展性、成本效益和易于对准进行制造。当应用于由常规光源产生的多色和发散光束时，该方法能够检测到与最先进的乳房X光照相技术兼容的、焦点高达100μm的无准直、无光圈光源的强相位效应。当用于同步加速器时，它可以使对比度比其他方法增加数量级。对于相干源和非相干源都证明了稳健的相位恢复，另外的优点是与高X射线能量兼容，并且易于同时实现两个方向的相位灵敏度。本文对这些成果进行了简要总结，并对其中一些关键成果进行了评述。
We have developed a totally incoherent, non-interferometric x-ray phase contrast imaging (XPCI) method. This is based on the edge illumination (EI) concept developed at the ELETTRA synchrotron in Italy in the late `90s. The method was subsequently adapted to the divergent beam generated by a conventional source, by replicating it for every detector line through suitable masks. The method was modelled both with the simplified ray-tracing and with the more rigorous wave-optics approach, and in both cases excellent agreement with the experimental results was found. The wave-optics model enabled assessing the methods' coherence requirements, showing that they are at least an order of magnitude more relaxed than in other methods, without this having negative consequences on the phase sensitivity. Our masks have large pitches (up to 50 times larger than in grating interferometry, for example), which allows for manufacturing through standard lithography, scalability, cost-effectiveness and easiness to align. When applied to a polychromatic and divergent beam generated by a conventional source, the method enables the detection of strong phase effects also with uncollimated, unapertured sources with focal spots of up to 100 μm, compatible with the state-of-the-art in mammography. When used at synchrotrons, it enables a contrast increase of orders of magnitude over other methods. Robust phase retrieval was proven for both coherent and incoherent sources, and additional advantages are compatibility with high x-ray energies and easy implementation of phase sensitivity in two directions simultaneously. This paper briefly summarizes these achievements and reviews some of the key results.