Fu Jian, Velroyen Astrid, Tan Renbo, Zhang Junwei, Chen Liyuan, Tapfer Arne, Bech Martin, Pfeiffer Franz
Beijing University of Aeronautics and Astronautics, 100191 Beiijng, China.
Opt Express. 2012 Sep 10;20(19):21512-9. doi: 10.1364/OE.20.021512.
Most existing differential phase-contrast computed tomography (DPC-CT) approaches are based on three kinds of scanning geometries, described by parallel-beam, fan-beam and cone-beam. Due to the potential of compact imaging systems with magnified spatial resolution, cone-beam DPC-CT has attracted significant interest. In this paper, we report a reconstruction method based on a back-projection filtration (BPF) algorithm for cone-beam DPC-CT. Due to the differential nature of phase contrast projections, the algorithm restrains from differentiation of the projection data prior to back-projection, unlike BPF algorithms commonly used for absorption-based CT data. This work comprises a numerical study of the algorithm and its experimental verification using a dataset measured with a three-grating interferometer and a micro-focus x-ray tube source. Moreover, the numerical simulation and experimental results demonstrate that the proposed method can deal with several classes of truncated cone-beam datasets. We believe that this feature is of particular interest for future medical cone-beam phase-contrast CT imaging applications.
大多数现有的微分相衬计算机断层扫描（DPC-CT）方法基于三种扫描几何结构，分别由平行束、扇形束和锥形束描述。由于具有放大空间分辨率的紧凑型成像系统的潜力，锥形束DPC-CT引起了广泛关注。在本文中，我们报告了一种基于反投影滤波（BPF）算法的锥形束DPC-CT重建方法。由于相衬投影的微分性质，该算法在反投影之前不对投影数据进行微分，这与通常用于基于吸收的CT数据的BPF算法不同。这项工作包括对该算法的数值研究及其使用三光栅干涉仪和微焦点X射线管源测量的数据集进行的实验验证。此外，数值模拟和实验结果表明，所提出的方法可以处理几类截断的锥形束数据集。我们认为，这一特性对于未来的医学锥形束相衬CT成像应用特别有意义。
