基于整数规划的永磁型磁共振成像装置主磁体的无源匀场技术研究  

A Passive Shimming Method Based on Integer Programming for Permanent Magnet of MRI Devices

作　　者：王恩龙[1] 谢德馨[2] 张艳丽[2] 任自艳[2] 

机构地区：[1]特变电工沈阳变压器集团有限公司,沈阳110025 [2]沈阳工业大学电气工程学院,沈阳110178

出　　处：《中国生物医学工程学报》2008年第4期533-536,共4页Chinese Journal of Biomedical Engineering

基　　金：高等学校博士学科点专项科研基金资助项目(20050142003)

摘　　要：为了符合成像标准,磁共振成像(MRI)设备要求主磁体能在较大的成像空间内产生高均匀度的磁场。但由于加工误差,实际磁场的均匀度远不能达到预定的要求,需要采用特殊方法进行匀场。本研究提出一种基于整数规划算法的无源匀场方法,将磁体的匀场问题提炼为整数规划问题,并编制了相应的匀场软件。通过在磁共振主磁体生产厂家进行的无源匀场实验,使得磁场的不均匀度从1549.7898×10-6降低到1129.9105×10-6,即均匀度提高了27%,证明该方法在一定程度上能够快速、有效地完成匀场过程,提高磁场的均匀度。In order to match the imaging standard, the Magnetic Resonance Imaging （MRI） device requires high field homogeneity in a large imaging region. Owing to the manufacturing tolerances that reduce the field homogeneity, some pest-manufacturing field corrections are required to bring the magnetic field uniformities to an acceptable level. Based on integer programming algorithm and basic theories of shimming, a new passive shimming method was proposed. The results showed that the un-uniformity was reduced from 1549.7898 × 10^-6 to 1129.9105 × 10^-6 by experiments of shimming in the MRI devices manufactory, meaning that the uniformity increased by 27%. The proposed method is effective and fast in improving the field uniformity of the imaging region at a certain extent.

关 键 词：磁共振成像 均匀度 整数规划 无源匀场 

分 类 号：R318[医药卫生—生物医学工程]