In Vitro Validation of an Artefact Suppression Algorithm in X-Ray Phase-Contrast Computed Tomography.
In Vitro Validation of an Artefact Suppression Algorithm in X-Ray Phase-Contrast Computed Tomography.
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DOI：
10.1371/journal.pone.0135654
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Ando M
中科院分区：
文献类型：
--
作者：
Sunaguchi N;Yuasa T;Hirano S;Gupta R;Ando M
X射线相衬断层扫描可以显著提高传统衰减对比成像的对比度分辨率，特别是对于具有非常相似衰减的软组织结构。正如在基于衰减的断层摄影中一样，相位对比断层摄影需要聚集射束方向与由沿着沿着X射线射束路径的个体体素引起的增量方向改变的线性相关性。生物标本中的钙化等致密物体违反了这一条件。在这种结构的附近存在广泛的光束偏转伪影，因为它们由于折射率的大差异而导致波前的大失真;对于光束方向的这种大变化，硅分析器晶体的透射率饱和并且不再线性地依赖于折射角。本文描述了一种方法，通过该方法可以克服这些影响，并且可以在这种伪影产生结构附近保留相位断层扫描的优良软组织对比度。
X-ray phase-contrast tomography can significantly increase the contrast-resolution of conventional attenuation-contrast imaging, especially for soft-tissue structures that have very similar attenuation. Just as in attenuation-based tomography, phase contrast tomography requires a linear dependence of aggregate beam direction on the incremental direction alteration caused by individual voxels along the path of the X-ray beam. Dense objects such as calcifications in biological specimens violate this condition. There are extensive beam deflection artefacts in the vicinity of such structures because they result in large distortion of wave front due to the large difference of refractive index; for such large changes in beam direction, the transmittance of the silicon analyzer crystal saturates and is no longer linearly dependent on the angle of refraction. This paper describes a method by which these effects can be overcome and excellent soft-tissue contrast of phase tomography can be preserved in the vicinity of such artefact-producing structures.