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一种结合快速L1范数最小化算法的柱面匀场线圈目标场设计方法

DOI: 10.13334/j.0258-8013.pcsee.2014.27.022, PP. 4737-4742

Keywords: 匀场线圈,核磁共振成像,最小均方差,L2范数,L1范数,目标场方法

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Abstract:

目标场方法由Turner于1986年提出,到目前为止该方法已成为核磁共振成像系统中匀场、梯度线圈设计的一种主流方法。各种改进的目标场方法纷纷涌现。为解决线圈设计中的有限尺寸问题,Forbes和Crozier提出了一种新方法,该方法预先通过三角函数来约束线圈面上的电流密度分布,为克服方程求解过程中的病态问题,对电流密度表达式中的待定系数采用最小均方差(leastsquare,LS)和L2范数相结合的方法来进行估计,成功得到了有限长匀场线圈的设计结果。该文采用最小均方差和L1范数结合的方法来对面电流密度分解表达式中的未知系数进行估计,并将该方法应用于核磁共振成像(magneticresonanceimaging,MRI)系统的匀场线圈设计中。系统主磁体长度为3m,室温孔直径为1.6m,目标区域(regionofinterest,ROI)直径为0.4m。算例采用Matlab仿真平台,结果表明该文提出的LS-L1目标场方法相比于传统的LS-L2目标场方法磁场偏差更小、效果更好。

References

[1]  Turner R.A target field approach to optimal coil design [J].IEEE Trans. on Applied Physics,1986,19(8):147-151.
[2]  Turner R.Gradient coil design:a review of methods [J].IEEE Trans. on Magnetic Resonance Imaging,1993,11(7):903-920.
[3]  Yoda K.Analysis design method of self-shielded planar coils[J].IEEE Trans. on Applied Physics,1990(67):4349-4353.
[4]  白烨,王秋良,余运佳,等.一种基于目标场法的球型线圈设计方法[J].中国电机工程学报,2004,24(6):132-136.Bai Ye,Wang Qiuliang,Yu Yunjia,et al.An approach to spherical coils design based on the target field approach [J].Proceedings of the CSEE,2004,24(6):132-136(in Chinese).
[5]  Forbes L K,Crozier S.A novel target-field method for finite-length magnetic resonance shim coils:part1 zonal shims[J].IEEE Trans. on Applied Physics,2001,34(1):3447-3455.
[6]  Forbes L K,Crozier S.A novel target-field method for finite-length magnetic resonance shim coils:part2 tesseral shims[J].IEEE Trans. on Applied Physics,2002,35(1):839-849.
[7]  Forbes L K,Crozier S.A novel target-field method for finite-length magnetic resonance shim coils:part3 shielded zonal and tesseral coils[J].IEEE Trans. on Applied Physics,2003,36(1):68-80.
[8]  Forbes L K,Crozier S.Novel target-field method for designing shielded biplanar shim and gradient coils[J].IEEE Trans. on Magnetics,2004,41(6):2134-2144.
[9]  Liu Wentao,Zu Donglin,Tang Xin,et al. Target-field method for MRI biplanar gradient coil design[J].Applied physics,2007,40(15):4418-4424.
[10]  Li Xia,Xie Dexin.Design of finite size uniplanar gradient coil for fully open MRI system with horizontal magnetic field[C]//World Automation Congress(WAC).Waikoloa,America:WAC,2008:1816-1819.
[11]  You Xiaofei,Hu Lili.Biplanar shim coil design for 1.5 T permanent magnet of in vivo animal MRI[J].IEEE Trans. on Applied Superconductivity,2010,20(3):1045-1049.
[12]  胡格丽,王秋良,倪志鹏,等.超导MRI柱面梯度线圈的目标场设计方法[J].中国电机工程学报,2012,32(增刊):276-280.Hu Geli,Wang Qiuliang,Ni Zhipeng,et al.Target field method for superconducting MRI cylindrical gradient coil design[J].Proceedings of the CSEE,2012,32 (Supplement):276-280(in Chinese).
[13]  Crozier S,Forbes L K.The design of transverse gradient coils of restricted length by simulated annealing[J].IEEE Trans. on Magnetic Resonance Imaging,1994,107(2):126-128.
[14]  Peters A M,Bowtell R W.Biplanar gradient coil design by simulated annealing[J].IEEE Trans. on Magnetic Resonance Imaging,1994,2(3):387-389.
[15]  Tomasi D,Caparelli E C.Fast optimization of a biplanar gradient coil set[J].IEEE Trans. on Magnetic Resonance,1999,140(2):325-339.
[16]  Poole M,Bowtell R.Novel gradient coils designed using a boundary element method[J].Concepts in Magnetic Resonance Part B:Magnetic Resonance Engineering,2007,31B(3):162-175.
[17]  Lopez H S,Liu F.Equivalent magnetization current method applied to the design of gradient coils for magnetic resonance imaging[J].IEEE Trans. on Magnetics,2009,45(2):767-775.
[18]  While P T,Forbes L K.3D gradient coil design—initial theoretical framework[J].IEEE Transactions on Biomedical Engineering,2009,56(4):1169-1183.
[19]  While P T,Forbes L K.3D gradient coil design toroidal surfaces[J].IEEE Transactions on Magnetic Resonance,2009,198(1):31-40.
[20]  Tomasi D.Stream function optimization for gradient coil design[J].IEEE Trans. on Magnetic Resonance Imaging,2001,45(3):505-512.
[21]  Kukreja S L,Löfberg J,Brenner M J.A least absolute shrinkage and selection operator(LASSO) for nonlinear system identification[C]//14th IFAC Symposium on System Identification.Australia:IFAC,2006:814-819.
[22]  Beck A,Teboulle M.A fast iterative shrinkage- thresholding algorithm for linear inverse problems [J].SIAM Journal on Imaging Sciences,2009,2(1):183-202.
[23]  Brideson M A,Forbes L K.Determining complicated winding patterns for shim coils using stream functions and the target-field method[J].Concepts in Magnetic Resonance,2002,14(1):9-18.
[24]  Rom’eo F,Hoult D I.Magnet field profiling:analysis and correcting coil design[J].IEEE Trans. on Magnetic Resonance Imaging,1984,1(1):44-65.

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