Sun Yi, Zhu Peiping, Yu Jian, Chen Xin
Department of Electronics Engineering of Dalian University of Technology, Dalian, Liao Ning, PR China.
Comput Med Imaging Graph. 2007 Sep;31(6):383-9. doi: 10.1016/j.compmedimag.2007.02.017. Epub 2007 Apr 10.
Conventional computerized tomography (CT) technique is based on the absorption contrast. In recent years, X-ray phase-contrast CT (PCCT) has been developing rapidly. It uses the phase information to reconstruct the object and provide high contrast and spatial resolution. Diffraction enhanced imaging (DEI) method is one of the three phase-sensitive X-ray imaging techniques. DEI method employs an analyzer crystal to extract the object's refraction information which can be used for CT. However, when DEI refraction CT is combined with the conventional CT algorithm, it should be satisfied that the refraction information of an arbitrary point in the object is invariable at every projection view. In this paper, the invariance condition of refraction information is analyzed and two feasible methods are provided for reconstruction. Using these two methods, two samples of weak absorption are reconstructed with the experimental data obtained at Beijing Synchrotron Radiation Facility (BSRF).
传统的计算机断层扫描（CT）技术基于吸收对比度。近年来，X射线相衬CT（PCCT）发展迅速。它利用相位信息重建物体并提供高对比度和空间分辨率。衍射增强成像（DEI）方法是三种相敏X射线成像技术之一。DEI方法采用分析晶体提取可用于CT的物体折射信息。然而，当DEI折射CT与传统CT算法结合时，应满足物体中任意点的折射信息在每个投影视图中不变。本文分析了折射信息的不变性条件，并提供了两种可行的重建方法。利用这两种方法，用在北京同步辐射装置（BSRF）获得的实验数据重建了两个弱吸收样品。
