Ge Yongshuai, Li Ke, Garrett John, Chen Guang-Hong
Opt Express. 2014 Jun 16;22(12):14246-52. doi: 10.1364/OE.22.014246.
Grating-based x-ray differential phase contrast imaging (DPCI) often uses a phase stepping procedure to acquire data that enables the extraction of phase information. This method prolongs the time needed for data acquisition by several times compared with conventional x-ray absorption image acquisitions. A novel analyzer grating design was developed in this work to eliminate the additional data acquisition time needed to perform phase stepping in DPCI. The new analyzer grating was fabricated such that the linear grating structures are shifted from one detector row to the next; the amount of the lateral shift was equal to a fraction of the x-ray diffraction fringe pattern. The x-ray data from several neighboring detector rows were then combined to extract differential phase information. Initial experimental results have demonstrated that the new analyzer grating enables accurate DPCI signal acquisition from a single x-ray exposure like conventional x-ray absorption imaging.
基于光栅的X射线微分相衬成像（DPCI）通常采用相移步骤来获取能够提取相位信息的数据。与传统的X射线吸收图像采集相比，这种方法将数据采集所需的时间延长了数倍。在这项工作中，开发了一种新型分析器光栅设计，以消除DPCI中执行相移所需的额外数据采集时间。制作的新型分析器光栅使线性光栅结构从一个探测器行转移到下一个探测器行；横向偏移量等于X射线衍射条纹图案的一部分。然后将来自几个相邻探测器行的X射线数据组合起来以提取微分相位信息。初步实验结果表明，新型分析器光栅能够像传统X射线吸收成像一样，通过单次X射线曝光准确采集DPCI信号。
