基于图像域的PROPELLER磁共振仿射运动校正新算法  

A New Algorithm for Affine Motion Compensation in PROPELLER MRI Based on Image Domain

作　　者：宋燕丽[1] 冯衍秋[1] 刘小武[1] 周爱珍[1] 王聪[1] 陈武凡[1] 

机构地区：[1]南方医科大学生物医学工程学院医学信息研究所,广州510515

出　　处：《生物医学工程学杂志》2011年第6期1194-1199,共6页Journal of Biomedical Engineering

基　　金：国家重点基础研究发展规划(973计划)项目资助(2010CB732502

摘　　要：在对人体腹部或其他软组织进行PROPELLER磁共振成像(MRI)过程中,成像结果会有不同程度的仿射运动伪影。迄今为止提出的比较好的仿射运动校正方法是基于频率域的,即用仿射运动信息对k空间条进行校正后网格化重建得到最终图像。但结果中会有混叠现象,并且在一些细节上有伪影存在。本文提出一种新的PRO-PELLER仿射校正方法,将仿射运动模型加入到基于图像域的PROPELLER磁共振图像重建过程中,首先在图像域通过图像配准算法获得仿射运动信息,然后利用仿射信息校正k空间坐标从而完成对k空间条的密度补偿,再通过逆傅立叶变换得到各个子图像并在图像域进行仿射校正,最后通过旋转完成线性叠加得到最终结果。仿真实验表明,相对于现有的PROPELLER仿射校正算法,本文所提算法对于仿射运动造成的伪影具有更好的校正效果。Affine motion is common during PROPELLER magnetic resonance imaging （MRI） in abdomen or other soft tissues. The current algorithm, up till now, for affine motion compensation is based on frequency domain, which compensates the motion in k space and then reconstruct the final image based on gridding method. But aliasing and some tiny artifacts may exist. This paper proposed a new algorithm for affine motion compensation based on image domain. Firstly, exact affine motion information was obtained through the image registration, secondly k space coordinate was corrected for compensating the k space strips sampling density, then the images obtained from inverse FFT was compensated using motion information, finally the final results were composited after rotation. The experimental results showed that the proposed method could more effectively suppress the motion artifacts compared to the current algorithm.

关 键 词：磁共振成像 PROPELLER 仿射运动伪影校正 图像域 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]