Passive shimming based on mixed integer programming for MRI magnet  

作　　者：YOU XiaoFei WANG Zheng ZHANG XiaoBing YANG WenHui SONG Tao 

机构地区：[1]Institute of Electrical Engineering,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences

出　　处：《Science China(Technological Sciences)》2013年第5期1208-1212,共5页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.50807050)

摘　　要：A mathematical model based on mixed integer programming is presented in this paper for the passive shimming of magnet in magnetic resonance imaging(MRI) scanner.In this model,the magnetic field inhomogeneity tolerance and the central value of the magnetic field after shimming are programmed together with the volume of each shim piece as the variables,which increases the degree of freedom and guarantees a better solution.The magnetic field inhomogeneity tolerance after shimming with a weighting coefficient and the total volume of shim pieces are both contained in the objective function of the model.By assigning different values to the weighting coefficient in the objective function,different shimming plans with different emphases can be obtained.A simulation test has been carried out on a small permanent magnet with frame structure.Several solutions are given and compared in this paper,which indicates that a practical shimming plan can be obtained quickly by solving this model.

关 键 词：mixed integer programming passive shimming magnetic resonance imaging （MRI） 

分 类 号：O482.531[理学—固体物理] O221.4[理学—物理]