基于正交图像矩的不完全投影数据CT图像重建研究

项目名称： 基于正交图像矩的不完全投影数据CT图像重建研究

项目编号： No.31200747

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 生物物理、生化与生物分子学、生物力学与组织工程

项目作者： 戴修斌

作者单位： 南京邮电大学

项目金额： 23万元

中文摘要： 由于CT扫描产生的X射线辐射易诱发人体新陈代谢异常乃至癌症等疾病，所以辐射剂量问题引起了较大关注。缩小CT设备扫描范围是临床上减少X射线辐射剂量的常用有效方法，但会使所获CT投影数据部分缺失，从而导致重建图像中出现大量噪声和伪影，降低了CT重建图像质量，最终影响临床医生对异常组织的确诊率。项目旨在利用具有全局和局部特征描述能力的正交图像矩，构建(1)正交图像矩和截断投影数据之间线性关系；(2)离散正交图像矩和投影数据之间线性关系；(3)三维离散旋转正交矩和锥形束CT、螺旋CT投影数据之间线性关系，然后根据这些线性关系直接针对缺失投影数据进行非迭代估计，补全投影数据，使得在部分投影数据缺失情况下重建图像质量达到或接近投影数据完全情况下的图像质量，满足临床诊断的要求。项目研究成果对目前CT成像设备低辐射剂量条件下图像重建关键技术的研究与创新具有重要的现实意义和临床应用价值。

中文关键词： 有限角度CT图像重建；锥形束CT；正交图像矩；低剂量；

英文摘要： Since X-ray radiation in CT scan will lead to abnormal metabolism and even cancer, the problem of radiation dose catchs more and more attensions. Reducing the scanning range of CT devices is the efficient method to reduce the X-ray radiation, which is widely used in clinic. However, that makes the acquired CT projection data incomplete, which will bring about severe noises and artifacts and degrade quality of the reconstructed CT images. Eventually, the diagnosis to the abnormal tissues could be affected in a wrong way. For the purpose of providing the clinically satisfactory CT images with low-dose X-ray radiation, this project makes use of the good performance of orthogonal image moment in global or local feature description and constructs (1). the linear relationship between orthogonal moments and truncated CT projections; (2).the linear relationship between discrete orthogonal moments and CT fan-beam projections; (3).the linear relationships between the three dimensional rotational orthogonal moments and cone-beam CT projection, and helical CT projection to rapidly estimate the missing projections using non-iterative method. The new methods can provide the CT images whose qualities are comparable to the ones obtained in high radiation dose. This project has great clinic values and important meanings to the d

英文关键词： limited-view CT reconstruction；cone-beam CT；orthogonal image moment；low dose；