基于动态规划的永磁MRI磁体的无源匀场  

Passive shimming of permanent magnet for MRI based on dynamic programming

作　　者：谢德馨[1] 王恩龙[1] 张艳丽[1] 

机构地区：[1]沈阳工业大学电气工程学院,沈阳110023

出　　处：《沈阳工业大学学报》2007年第4期396-399,共4页Journal of Shenyang University of Technology

基　　金：国家自然科学基金资助项目(50377027);高等学校博士学科点专项科研基金资助项目(20050142003)

摘　　要：磁共振成像要求主磁体能在较大的成像空间内产生高均匀度的磁场,由于加工误差的存在,实际上磁场的均匀度远不能达到预定要求,需要采用特殊方法进行匀场,从而提高成像的质量.提出一种基于动态规划的无源匀场方法,并编制了相应的匀场软件;分别在双柱型磁体和传统C型磁体上进行了匀场实验,大量实验结果表明该方法可以有效提高磁场均匀度.证明了基于动态规划的无源匀场方法能够快速、有效地完成匀场过程,提高磁场的均匀度.The magnetic resonance imaging device requires high field uniformity in a large imaging region. Owing to the manufacturing tolerances that reduce the field homogeneity, some post-manufacturing field corrections are required to bring the magnetic field uniformities to an acceptable level. And thus, the imaging quality of MRI can be improved. A new passive shimming method has been developed based on dynamic programming algorithm. Shimming experiments were performed respectively in queen-post magnet and traditional C-shape magnet. The results show that the developed method can enhance the homogeneity of magnetic field effectively. The present method has been proven effective and fast in improving the field uniformity of the imaging region through several experiments.

关 键 词：磁共振成像 均匀度 动态规划 无源匀场 匀场实验 

分 类 号：O221.3[理学—运筹学与控制论]