减少锥束CT中几何对准不良引起的伪影。

Reduction of artifacts induced by misaligned geometry in cone-beam CT.

作者信息

Sun Yi, Hou Ying, Hu Jiasheng

机构信息

School of Electronic and Information Engineering, Dalian University of Technology, 2 Linggong Rd., Dalian 116023, China.

出版信息

IEEE Trans Biomed Eng. 2007 Aug;54(8):1461-71. doi: 10.1109/TBME.2007.891166.

DOI:10.1109/TBME.2007.891166

PMID:17694867

Abstract

The quality of computed tomography (CT) images frequently suffers from artifacts caused by scanner misalignments. In this paper, we discuss the results of our improved approximate cone-beam reconstruction formula, which corrects for the mechanical misalignment of the scanner. Based on the general filtered back-projection (FBP) algorithm proposed by Feldkamp, the new formula reduces the artifacts in reconstructed images. Six parameters are employed to describe the scanner misalignment. Experimental results show that the images reconstructed by using the new formula are clearer than those reconstructed by using the general FBP algorithm in a misaligned system. Through the new formula, we have reduced the artifacts caused by misalignment.

摘要

计算机断层扫描（CT）图像的质量常常受到扫描仪校准不当所导致的伪影影响。在本文中，我们讨论了改进后的近似锥束重建公式的结果，该公式可校正扫描仪的机械校准不当问题。基于费尔德坎普提出的通用滤波反投影（FBP）算法，新公式减少了重建图像中的伪影。使用六个参数来描述扫描仪的校准不当情况。实验结果表明，在校准不当的系统中，使用新公式重建的图像比使用通用FBP算法重建的图像更清晰。通过新公式，我们减少了校准不当所导致的伪影。