衍射增强成像提取多种信息的简便方法研究

衍射增强相位衬度成像中的信息分离研究一直以来都是相关研究人员重点关注的方向之一. 本文在利用余弦函数拟合衍射增强成像中的摇摆曲线的基础上, 推导出了峰位像、左腰像和右腰像的余弦函数表达式以及吸收像、折射角像和散射角方差像的解析表达式, 形成了一种基于衍射增强成像的简便信息分离方法. 该方法只需利用摇摆曲线左腰、右腰和峰位三幅图像, 就能提取出样品的吸收、折射和散射信息, 具有方法简便、样品所受辐射剂量低等优点. 对模型样品和真实样品的实验结果表明, 本文所提方法可成功对样品进行信息分离, 并且所获得的信息分离结果可以和目前常用的多图统计方法(至少需要7张图像)获得的实验结果相比较. 关键词： 衍射增强成像 相位衬度成像 样品信息提取

A simple method of extracting multiple-information with diffraction enhanced imaging

Sample information-extracting with diffraction enhanced imaging (DEI) has been one of the interesting areas for many years. Using cosine curve to fit rocking curve in DEI, we deduce the equations described by cosine functions for peak-position image, low- and high-angle image. The analytical expressions of absorption image, refractive angle image and scattering image are also developed. Then a simple method is proposed for sample information-extracting with DEI based on those deductions. This method can extract the absorption information, refractive angle information and scattering information of a sample using only three images, i.e. one peak-position, one low-angle image and on high-angle image, resulting in simple experimental process and low radiation dose introduced to sample by imaging process. The experiments are carried out on a standard sample and a real biological sample. For comparison, experiments are also carried out on the same two samples using the common multiple-image radiography (MIR) method, in which at least seven images should be used to extract sample information. Experimental results show that our new method does extract sample information successfully, and the results from our new method are comparable to those from the MIR method.
Keywords： diffraction enhanced imaging phase contrast imaging sample information-extraction