A motion artefact study and locally deforming objects in computerized tomography
A motion artefact study and locally deforming objects in computerized tomography
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DOI：
10.1088/1361-6420/aa8d7b
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发表时间：
2017-10
期刊：
影响因子：
2.1
通讯作者：
B. Hahn
中科院分区：
文献类型：
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作者：
B. Hahn
在计算机断层摄影中的数据收集期间对象的运动可以在重建图像中引入运动伪影。它们可以通过在重构步骤中采用关于动态行为的信息来减少。然而，在实践中，有关运动的不准确性是不可避免的。在这篇文章中，我们给出了一个明确的特征是什么是可见的图像重建算法与不正确的运动信息。然后，我们使用这个结果来详细研究局部变形对象的情况，即对象的各个部分具有不同的动态行为。在这种情况下，我们证明了额外的文物出现由于拉冬变换的全局性质，即使运动是完全已知的。基于我们的分析，我们提出了一个数值方案，以减少这些文物的重建图像。所有结果都通过数值例子加以说明。
Movements of the object during the data collection in computerized tomography can introduce motion artefacts in the reconstructed image. They can be reduced by employing information about the dynamic behaviour within the reconstruction step. However, inaccuracies concerning the movement are inevitable in practice. In this article, we give an explicit characterization of what is visible in an image obtained by a reconstruction algorithm with incorrect motion information. Then, we use this result to study in detail the situation of locally deforming objects, i.e. individual parts of the object have a different dynamic behaviour. In this context, we prove that additional artefacts arise due to the global nature of the Radon transform, even if the motion is exactly known. Based on our analysis, we propose a numerical scheme to reduce these artefacts in the reconstructed image. All our results are illustrated by numerical examples.