衍射增强成像信息分离方法研究

衍射增强成像（DEI）是一种功能强大的相位衬度成像技术，对于软组织，它能获得比基于吸收的传统X射线成像技术更高的衬度.研究了一种基于DEI的信息分离方法，它能同时获得三种参数图像，即吸收像、折射像和小角散射像.信息分离利用解析方程求解，获得的参数图像质量取决于在三个不同的分析晶体角度处获得的DEI图像.利用矩阵条件数对方程求解的稳定性进行了讨论，推导出理论上的折射角和小角散射宽度的最大值.最后，利用豚鼠耳蜗DEI图像对研究结果进行了验证. 关键词： 信息分离 衍射增强成像 矩阵条件数 豚鼠耳蜗

The study of information extraction based on diffraction enhanced imaging

Diffraction enhanced imaging （DEI） is a powerful phase sensitive technique that generates improved contrast of soft tissues compared to the conventional X ray imaging. In this paper, an information extraction method is investigated based on diffraction enhanced imaging, which simultaneously produces three parametric images, depicting separately an object's projected X ray absorption, refraction and ultra small angle X ray scattering （USAXS） properties. The information extraction is resolved using analytic reconstruction formulae, and the quality of the obtained parametric images depends on the input images acquired at three distinct analyser crystal orientations. The stability of the reconstruction procedure is discussed using the condition number of matrix, and the theoretical maxima of the refraction angle and USAXS distribution width are given. Finally, validation studies are conducted by use of guinea pig cochleae DEI image.