任务导向的X射线光栅相位衬度成像方法的定量评价

项目名称： 任务导向的X射线光栅相位衬度成像方法的定量评价

项目编号： No.U1532113

项目类型： 联合基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 王志立

作者单位： 合肥工业大学

项目金额： 60万元

中文摘要： X射线光栅相位衬度成像方法能够有效利用常规光源进行高灵敏度的相衬成像，因而在临床医学、材料科学等领域具有广阔的应用前景，成为近年来X射线成像领域的研究热点之一。最近的研究报道证实，X射线光栅相衬成像方法能够在软组织等弱吸收特征的可视化方面发挥重要作用。然而，目前还缺乏对这种可视化能力的定量表征。当代图像科学理论已经明确指出任务导向的图像质量评价才是图像质量和成像方法的最终评价标准。图像质量的物理评价不能够客观地反映相位衬度对于完成特征探测任务的直接贡献。为此，本项目提出任务导向的X射线光栅相位衬度成像方法的定量评价研究，利用傅里叶光学理论和统计决策理论，建立理想/非理想观测者信噪比的计算模型，作为评价X射线光栅相衬成像方法的客观依据。本项目研究工作的开展将使得人们能够更加深刻、客观地理解相位衬度在弱吸收特征检测方面的贡献，推动X射线相位衬度成像技术在临床医学诊断等领域的实际应用。

中文关键词： X射线成像；相位衬度；图像质量评价；信噪比；光栅干涉仪

英文摘要： Grating-based X-ray phase contrast imaging can efficiently utilize conventional X-ray sources to perform highly sensitive phase imaging. Therefore, it is expected that this method can find widespread potential applications in clinical medical imaging, materials science and many other fields, and has become a hot topic in X-ray imaging community. Recent research has confirmed that grating-based X-ray phase contrast imaging is very powerful in the visualization of weakly absorbing features. However, there is a lack of quantitative characterization of this visualization. Modern image science theory has point out definitely that task-based measures of image quality is the ultimate standard. Physical measure of image quality do not directly reveal how useful the image quality are for the facilitating a specified detection task..Therefore, this project proposes the research on task-based quantitative evaluation of grating-based X-ray phase contrast imaging. By use of Fourier optics theory and statistical decision theory, this research derives the calculation model of signal-to-noise ratios (SNRs) for ideal and non-ideal observer, respectively. The SNRs is then used as objective measure to evaluate grating-based phase contrast imaging. This project aims to provide an objective and comprehensive understanding of how phase contrast contributes to the detection of weakly absorbing features, and promote the widespread implementations of X-ray phase contrast imaging in clinical medical imaging and many other fields.

英文关键词： X-ray imaging;Phase contrast;Image quality assessment;Signal-to-noise ratio;Grating interferometry