Wang Zhili, Ren Kun, Shi Xiaomin, Ren Yuqi, Gao Kun, Wu Zhao
School of Electronic Science and Applied Physics, Hefei University of Technology, Anhui 230009, People's Republic of China.
Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, People's Republic of China.
J Synchrotron Radiat. 2019 Jan 1;26(Pt 1):215-219. doi: 10.1107/S1600577518016727.
A single-image method is proposed for quantitative phase retrieval in hard X-ray grating interferometry. This novel method assumes a quasi-homogeneous sample, with a constant ratio between the real and imaginary parts of its complex refractive index. The method is first theoretically derived and presented, and then validated by synchrotron radiation experiments. Compared with the phase-stepping method, the presented approach abandons grating scanning and multiple image acquisition, and is therefore advantageous in terms of its simplified acquisition procedure and reduced data-collection times, which are especially important for applications such as in vivo imaging and phase tomography. Moreover, the sample's phase image, instead of its first derivative, is directly retrieved. In particular, the stripe artifacts encountered in the integrated phase images are significantly suppressed. The improved quality of the retrieved phase images can be beneficial for image interpretation and subsequent processing. Owing to its requirement for a single image and its robustness against noise, the present method is expected to find use in potential investigations in diverse applications.
本文提出了一种用于硬X射线光栅干涉术中定量相位恢复的单图像方法。这种新方法假定样品为准均匀的，其复折射率的实部和虚部之间具有恒定的比率。该方法首先从理论上进行推导和阐述，然后通过同步辐射实验进行验证。与相移法相比，本文提出的方法摒弃了光栅扫描和多图像采集，因此在简化采集过程和减少数据采集时间方面具有优势，这对于体内成像和相位断层扫描等应用尤为重要。此外，直接恢复的是样品的相位图像，而不是其一阶导数。特别是，积分相位图像中遇到的条纹伪影得到了显著抑制。恢复后的相位图像质量的提高有助于图像解释和后续处理。由于其对单图像的要求以及对噪声的鲁棒性，预计本方法将在各种应用的潜在研究中得到应用。
