Thompson Darren A, Nesterets Yakov I, Pavlov Konstantin M, Gureyev Timur E
Commonwealth Scientific and Industrial Research Organisation, Clayton, Victoria, Australia.
University of New England, Armidale, New South Wales, Australia.
J Synchrotron Radiat. 2019 May 1;26(Pt 3):825-838. doi: 10.1107/S1600577519002133. Epub 2019 Apr 2.
The following article describes a method for 3D reconstruction of multi-material objects based on propagation-based X-ray phase-contrast tomography (PB-CT) with phase retrieval using the homogeneous form of the transport of intensity equation (TIE-Hom). Unlike conventional PB-CT algorithms that perform phase retrieval of individual projections, the described post-reconstruction phase-retrieval method is applied in 3D to a localized region of the CT-reconstructed volume. This work demonstrates, via numerical simulations, the accuracy and noise characteristics of the method under a variety of experimental conditions, comparing it with both conventional absorption tomography and 2D TIE-Hom phase retrieval applied to projection images. The results indicate that the 3D post-reconstruction method generally achieves a modest improvement in noise suppression over existing PB-CT methods. It is also shown that potentially large computational gains over projection-based phase retrieval for multi-material samples are possible. In particular, constraining phase retrieval to a localized 3D region of interest reduces the overall computational cost and eliminates the need for multiple CT reconstructions and global 2D phase retrieval operations for each material within the sample.
以下文章描述了一种基于基于传播的X射线相衬断层扫描（PB-CT）并使用强度传输方程的均匀形式（TIE-Hom）进行相位恢复的多材料物体三维重建方法。与执行单个投影相位恢复的传统PB-CT算法不同，所描述的重建后相位恢复方法在三维中应用于CT重建体积的局部区域。这项工作通过数值模拟展示了该方法在各种实验条件下的准确性和噪声特性，并将其与传统吸收断层扫描以及应用于投影图像的二维TIE-Hom相位恢复进行了比较。结果表明，三维重建后方法通常在噪声抑制方面比现有的PB-CT方法有适度的改进。还表明，对于多材料样本，相对于基于投影的相位恢复可能有很大的计算优势。特别是，将相位恢复限制在局部三维感兴趣区域可降低总体计算成本，并消除了对样本内每种材料进行多次CT重建和全局二维相位恢复操作的需要。
