De Witte Yoni, Boone Matthieu, Vlassenbroeck Jelle, Dierick Manuel, Van Hoorebeke Luc
Department of Subatomic and Radiation Physics, Ghent University, Proeftuinstraat 86, 9000 Ghent, Belgium.
J Opt Soc Am A Opt Image Sci Vis. 2009 Apr;26(4):890-4. doi: 10.1364/josaa.26.000890.
When a very-low-absorbing sample is scanned at an x-ray computed tomography setup with a microfocus x-ray tube and a high-resolution detector, the obtained projection images contain not only absorption contrast but also phase contrast. While images without a phase signal can be reconstructed very well, such mixed phase and absorption images give rise to severe artifacts in the reconstructed slices. A method is described that applies a correction to these mixed projections to remove the phase signal. These corrected images can then be processed using a standard filtered backprojection algorithm to obtain reconstructions with only few or no phase artifacts. This new method, which we call the Bronnikov-aided correction (BAC), can be used in a broad variety of applications and without much additional effort. It is tested on a biological and a pharmaceutical sample, and results are evaluated and discussed by comparing them with those of conventional reconstruction methods.
当在配备微焦点X射线管和高分辨率探测器的X射线计算机断层扫描装置上对吸收极低的样品进行扫描时，所获得的投影图像不仅包含吸收对比度，还包含相位对比度。虽然没有相位信号的图像可以很好地重建，但这种相位和吸收混合的图像会在重建切片中产生严重的伪影。本文描述了一种对这些混合投影进行校正以去除相位信号的方法。然后可以使用标准的滤波反投影算法对这些校正后的图像进行处理，以获得仅有很少或没有相位伪影的重建图像。这种我们称为布龙尼科夫辅助校正（BAC）的新方法可以广泛应用，且无需太多额外工作。它在一个生物样品和一个药物样品上进行了测试，并通过与传统重建方法的结果进行比较来评估和讨论结果。
