摘要
平方和算法是多线圈采集技术与并行成像中常用的一种图像重建方法。但是,在数据采集过程中,某些类型的运动常常会使个别位置上的线圈数据发生异常,采用平方和算法会对最终的重建图像质量产生很大影响。本研究提出一种新的并行磁共振图像重建算法——加权平方和方法。算法以线圈图像间最大互信息量作为判据来统计破坏数据,在之后的图像结合过程中赋予不同的权值,最大限度地降低破坏数据对最终结合图像造成的影响,有效解决运动对原有算法造成的破坏。本算法分别对多线圈并行采集的体模数据与真实脑部数据进行了实验,结果显示:相比于现有方法,新算法可以有效地抑制破坏数据在重建图像中产生的伪影,重建图像在细节分辨率上也有更好的表现。
Sum-of-Squares (SOS) is considered a common reconstruction method for phased array MRI with unknown coil sensitivity. However, some types of motion may only contaminate data from coil of individual position during the data acquisition, having a great effect on reconstructed image quality in using SOS method. In this article, an alternative technique called Weighted-Sum-of-Squares (WSOS) algorithm was proposed for phased array MRI to deal with the problem. This algorithm accurately estimated corrupt samples based on mutual information between the coil images, and then weights were redistributed utilizing estimative knowledge in the following combined process. In this way,the influence of corrupt samples was attenuated so that motion artifacts in reconstructed images could be effectively reduced. Phantom as well as in vivo experiments showed that the new method reduced the artifacts caused by the corrupt data in the reconstructed images and image resolution was significantly improved as well by comparing it to conventional method.
出处
《中国生物医学工程学报》
CAS
CSCD
北大核心
2007年第6期850-855,共6页
Chinese Journal of Biomedical Engineering
基金
国家自然科学基金重点项目(30730036)
国家"973"重点基础研究发展规划项目(2003CB716102)。