新型混合滤波器在FDK算法中的应用

摘要

目的 探讨新型混合滤波器在锥束CT图像重建FDK算法中的应用价值.方法对使用锥束CT图像质量检测模体CatPhan 500获得的投影数据进行FDK算法重建,重建过程中分别应用由R-L滤波器和S-L滤波器组成的传统混合滤波器及R-L滤波器和NEW滤波器组成的新型混合滤波器,比较两种混合滤波器重建图像的质量.结果与传统混合滤波器相比,新型混合滤波器重建图像的对比噪声比及空间均匀性有所提高,且图像噪声有所降低;而两种混合滤波器重建图像的空间分辨率无明显差别.结论 FDK算法中新型混合滤波器在重建图像空间分辨率无明显下降的情况下,提高了对比噪声比及空间均匀性,降低了图像噪声,因此新型混合滤波器的重建效果优于传统混合滤波器.%Objective To evaluate the application value of a new mixed filter in the FDK algorithm for cone-beam CT image reconstruction.Methods The reconstruction of projection data acquired with cone-beam CT image quality test phantom (CatPhan 500) was performed with FDK algorithm.The traditional mixed filter formed by R-L filter and S-L filter and the new mixed filter formed by R-L filter and NEW filter were used during the reconstruction process, respectively, and the reconstructed image quality obtained by the two mixed filters was compared.Results Compared with the traditional mixed filter, the image contrast noise ratio, space uniformity of the new mixed filter were improved, while the image noise was reduced.No obvious difference of spatial resolution was found in visual sensation between the reconstructed images of the two mixed filters.Conclusion The new mixed filter can improve the contrast noise ratio and space uniformity of the reconstructed image without the reduction of spatial resolution.Therefore, the reconstruction results of the new mixed filter is better than the traditional mixed filter.