计算机模拟CT滤波反投影重建的方法  

The Simulation of CT Filtering Projection Reconstruction Using Computer

作　　者：王志伟[1] 于强[1] 舒春梅[1] 谭润初[1] 贺奇才[1] 

机构地区：[1]中山大学中山医学院生物医学工程系,广东广州510080

出　　处：《中国医学物理学杂志》2010年第2期1737-1740,共4页Chinese Journal of Medical Physics

摘　　要：目的:选择合适的滤波函数处理对CT反投影图像进行滤波,从而达到消除反投影所产生的星形伪影的目的。使得CT滤波反投影重建的方法直观地演示出来,也便于比较不同滤波函数的效果,寻找更好的滤波函数。方法:采用计算机软件编程实现计算机模拟CT反投影重建,以VC软件平台IDE集成开发环境,开发出一个具有可视图形界面的上位机软件,通过选择不同的滤波反投影参数,对重建的图像的效果进行定量的比较,探讨滤波函数中不同参数对结果的影响。结果:通过软件编程实现了标准体模图像重建的模拟,界面简单,可以直观地对CT图像进行反投影重建,同时所选择的基于频率域变换的滤波函数也部分消除了重建过程中造成的星形伪影,提高了图像均匀度,使标准体模的重建图像达到预期的理想效果。结论:开发的软件实现了CT反投影重建,能够将标准体模反投影重建的成像过程以更清晰的方式展现出来,有利于在医学物理学理论课和实验课的教学中,直观演示星形伪影及滤波效果,使学生更好地学习CT技术的原理。也有利于尝试新的投影算法,寻找新的滤波函数。Objective： So far, CT back projection technology is already quite mature, this article is a basic research for CT back projection technology, which uses software method to realize back-projection technology, so that you can have a better understanding of CT back-projection technology. It uses computer software programming to realize computer simulation of CT back-projection reconstruction： algorithm is CT back projection algorithm. While realizing back-projection reconstruction, we can choose a suitable filtering function to process received image data in frequency domain, so as to achieve the purpose of the elimination of simple back-projection arising from star-shaped artifact. Methods： The programming environment uses VC soft- ware platform integrated development environment （DE）. It bases on the CT filtering back-projection reconstruction algorithm and develops a PC software of graphic user interface. By choosing the value of the various parameters related to the back-projection, we can obtain different effect of back-projection reconstruction image, so that we can compare the result of different parameters to get important factors which effects CT filter back-projection most. Results： We realize the simulation of image re- construction of standard phantom. The interface is easy, so makes it very convenient for deeper understanding of back-projection reconstruction, at the same time the filtering function based on the fequency domain also partly eliminates the star artifact caused by reconstruction process. The reconstruction image of the standard phantom achieves the desired effect. Conclusions： The software simulation of the back-projection reconstruction can show the process of reconstruction clearly. By change the val- ue of the parameters, we can have a better understanding of the reconstruction algorithm, so that we can find more suitable fil- tering function.

关 键 词：CT 滤波函数 滤波反投影(卷积反投影) 

分 类 号：R814.42[医药卫生—影像医学与核医学]