基于高维PDE投影恢复的低剂量CT重建方法  

Low-dose CT reconstruction based on high-dimensional partial differential equationprojection recovery

作　　者：牛善洲[1,2] 唐诗洲 黄舒彦 梁礼境 李硕 刘汉明[1] NIU Shanzhou;TANG Shizhou;HUANG Shuyan;LIANG Lijing;LI Shuo;LIU Hanming(School of Mathematics and Computer Science,Gannan Normal University,Ganzhou 341000,China;Ganzhou Key Laboratory of Computational Imaging,Gannan Normal University,Ganzhou 341000,China)

机构地区：[1]赣南师范大学数学与计算机科学学院,江西赣州341000 [2]赣南师范大学赣州市计算成像重点实验室,江西赣州341000

出　　处：《南方医科大学学报》2024年第4期682-688,共7页Journal of Southern Medical University

基　　金：国家自然科学基金(62261002);江西省科技创新杰出青年人才资助计划项目(20192BCB23019);江西省重点研发计划一般项目(20202BBE53024);江西省“双千计划”科技创新高端人才项目(jxsq2019201061)。

摘　　要：目的提出一种基于高维偏微分方程(PDE)投影恢复的低剂量CT重建方法。方法先将原始的投影数据映射到高维空间中,构造投影数据的高维表示,通过移动高维空间中的点来对高维表示进行更新,再使用偏微分方程对投影数据进行滤波,最后将恢复后的数据使用FBP算法重建出最终CT图像。结果在Shepp-Logan体模实验中,与FBP,PWLS-QM和TGV-WLS方法相比,新方法在相对均方根误差指标上分别降低了68.87%、50.15%和27.36%,结构相似性上分别提高了23.50%,8.83%和1.62%,特征相似性上分别提高了17.30%、2.71%和2.82%。在腹部临床数据实验中,与FBP,PWLS-QM和TGV-WLS方法相比,新方法在相对均方根误差中分别降低了42.09%、31.04%和21.93%,结构相似性上分别提高了18.33%、13.45%和4.63%,特征相似性上分别提高了3.13%、1.46%和1.10%。结论本研究提出的新方法在有效去除低剂量CT图像中的条形伪影和噪声的同时,可以保持图像的空间分辨率。Objective We propose a low-dose CT reconstruction method using partial differential equation(PDE)denoising under high-dimensional constraints.Methods The projection data were mapped into a high-dimensional space to construct a high-dimensional representation of the data,which were updated by moving the points in the high-dimensional space.The data were denoised using partial differential equations and the CT image was reconstructed using the FBP algorithm.Results Compared with those by FBP,PWLS-QM and TGV-WLS methods,the relative root mean square error of the Shepp-Logan image reconstructed by the proposed method were reduced by 68.87%,50.15%and 27.36%,the structural similarity values were increased by 23.50%,8.83%and 1.62%,and the feature similarity values were increased by 17.30%,2.71%and 2.82%,respectively.For clinical image reconstruction,the proposed method,as compared with FBP,PWLS-QM and TGV-WLS methods,resulted in reduction of the relative root mean square error by 42.09%,31.04%and 21.93%,increased the structural similarity values by 18.33%,13.45%and 4.63%,and increased the feature similarity values by 3.13%,1.46%and 1.10%,respectively.Conclusion The new method can effectively reduce the streak artifacts and noises while maintaining the spatial resolution in reconstructed low-dose CT images.

关 键 词：低剂量CT 偏微分方程 投影数据恢复 图像重建 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术] R814[自动化与计算机技术—计算机科学与技术]