Thompson Darren A, Nesterets Yakov I, Pavlov Konstantin M, Gureyev Timur E
J Opt Soc Am A Opt Image Sci Vis. 2023 Jun 1;40(6):1249-1259. doi: 10.1364/JOSAA.494293.
A new method is developed for 3D reconstruction of multimaterial objects using propagation-based x-ray phase-contrast tomography (PB-CT) with phase retrieval via contrast-transfer-function (CTF) formalism. The approach differs from conventional PB-CT algorithms, which apply phase retrieval to individual 2D projections. Instead, this method involves performing phase retrieval to the CT-reconstructed volume in 3D. The CTF formalism is further extended to the cases of partially coherent illumination and strongly absorbing samples. Simulated results demonstrate that the proposed post-reconstruction CTF method provides fast and stable phase retrieval, producing results equivalent to conventional pre-reconstruction 2D CTF phase retrieval. Moreover, it is shown that application can be highly localized to isolated objects of interest, without a significant loss of quality, thus leading to increased computational efficiency. Combined with the extended validity of the CTF to greater propagation distances, this method provides additional advantages over approaches based on the transport-of-intensity equation.
一种新方法被开发出来，用于使用基于传播的X射线相衬断层扫描（PB-CT）并通过对比度传递函数（CTF）形式进行相位恢复，来对多材料物体进行三维重建。该方法不同于传统的PB-CT算法，传统算法将相位恢复应用于单个二维投影。相反，此方法涉及对三维CT重建体积进行相位恢复。CTF形式进一步扩展到部分相干照明和强吸收样品的情况。模拟结果表明，所提出的重建后CTF方法提供了快速且稳定的相位恢复，产生的结果等同于传统的重建前二维CTF相位恢复。此外，结果表明应用可以高度局部化到感兴趣的孤立物体，而不会显著损失质量，从而提高了计算效率。结合CTF在更大传播距离上的扩展有效性，该方法相对于基于强度传输方程的方法具有额外优势。
