Vol. 94
Latest Volume
All Volumes
PIER 180 [2024] PIER 179 [2024] PIER 178 [2023] PIER 177 [2023] PIER 176 [2023] PIER 175 [2022] PIER 174 [2022] PIER 173 [2022] PIER 172 [2021] PIER 171 [2021] PIER 170 [2021] PIER 169 [2020] PIER 168 [2020] PIER 167 [2020] PIER 166 [2019] PIER 165 [2019] PIER 164 [2019] PIER 163 [2018] PIER 162 [2018] PIER 161 [2018] PIER 160 [2017] PIER 159 [2017] PIER 158 [2017] PIER 157 [2016] PIER 156 [2016] PIER 155 [2016] PIER 154 [2015] PIER 153 [2015] PIER 152 [2015] PIER 151 [2015] PIER 150 [2015] PIER 149 [2014] PIER 148 [2014] PIER 147 [2014] PIER 146 [2014] PIER 145 [2014] PIER 144 [2014] PIER 143 [2013] PIER 142 [2013] PIER 141 [2013] PIER 140 [2013] PIER 139 [2013] PIER 138 [2013] PIER 137 [2013] PIER 136 [2013] PIER 135 [2013] PIER 134 [2013] PIER 133 [2013] PIER 132 [2012] PIER 131 [2012] PIER 130 [2012] PIER 129 [2012] PIER 128 [2012] PIER 127 [2012] PIER 126 [2012] PIER 125 [2012] PIER 124 [2012] PIER 123 [2012] PIER 122 [2012] PIER 121 [2011] PIER 120 [2011] PIER 119 [2011] PIER 118 [2011] PIER 117 [2011] PIER 116 [2011] PIER 115 [2011] PIER 114 [2011] PIER 113 [2011] PIER 112 [2011] PIER 111 [2011] PIER 110 [2010] PIER 109 [2010] PIER 108 [2010] PIER 107 [2010] PIER 106 [2010] PIER 105 [2010] PIER 104 [2010] PIER 103 [2010] PIER 102 [2010] PIER 101 [2010] PIER 100 [2010] PIER 99 [2009] PIER 98 [2009] PIER 97 [2009] PIER 96 [2009] PIER 95 [2009] PIER 94 [2009] PIER 93 [2009] PIER 92 [2009] PIER 91 [2009] PIER 90 [2009] PIER 89 [2009] PIER 88 [2008] PIER 87 [2008] PIER 86 [2008] PIER 85 [2008] PIER 84 [2008] PIER 83 [2008] PIER 82 [2008] PIER 81 [2008] PIER 80 [2008] PIER 79 [2008] PIER 78 [2008] PIER 77 [2007] PIER 76 [2007] PIER 75 [2007] PIER 74 [2007] PIER 73 [2007] PIER 72 [2007] PIER 71 [2007] PIER 70 [2007] PIER 69 [2007] PIER 68 [2007] PIER 67 [2007] PIER 66 [2006] PIER 65 [2006] PIER 64 [2006] PIER 63 [2006] PIER 62 [2006] PIER 61 [2006] PIER 60 [2006] PIER 59 [2006] PIER 58 [2006] PIER 57 [2006] PIER 56 [2006] PIER 55 [2005] PIER 54 [2005] PIER 53 [2005] PIER 52 [2005] PIER 51 [2005] PIER 50 [2005] PIER 49 [2004] PIER 48 [2004] PIER 47 [2004] PIER 46 [2004] PIER 45 [2004] PIER 44 [2004] PIER 43 [2003] PIER 42 [2003] PIER 41 [2003] PIER 40 [2003] PIER 39 [2003] PIER 38 [2002] PIER 37 [2002] PIER 36 [2002] PIER 35 [2002] PIER 34 [2001] PIER 33 [2001] PIER 32 [2001] PIER 31 [2001] PIER 30 [2001] PIER 29 [2000] PIER 28 [2000] PIER 27 [2000] PIER 26 [2000] PIER 25 [2000] PIER 24 [1999] PIER 23 [1999] PIER 22 [1999] PIER 21 [1999] PIER 20 [1998] PIER 19 [1998] PIER 18 [1998] PIER 17 [1997] PIER 16 [1997] PIER 15 [1997] PIER 14 [1996] PIER 13 [1996] PIER 12 [1996] PIER 11 [1995] PIER 10 [1995] PIER 09 [1994] PIER 08 [1994] PIER 07 [1993] PIER 06 [1992] PIER 05 [1991] PIER 04 [1991] PIER 03 [1990] PIER 02 [1990] PIER 01 [1989]
2009-07-25
Magnetic Field in MRI Yokeless Devices: Analytical Approach
By
Progress In Electromagnetics Research, Vol. 94, 327-341, 2009
Abstract
This paper presents a three-dimensional analytical expressions for studying the static magnetic field produced by Magnetic Resonance Imaging structures. This medical imaging technique uses a very high and uniform magnetic field produced by ring permanent magnets with rotating polarizations. However, the manufacturing of such ring permanent magnets is difficult to realize. Consequently, such ring permanent magnets are replaced by assemblies of tile permanent magnets uniformly magnetized. Unfortunately, the magnetic field produced by these tile permanent magnets uniformly magnetized is both less important and less uniform than the one produced by an idealized ring permanent magnet. We propose in this paper to study the influence of the number of tile permanent magnets used on the magnetic field properties.
Citation
Romain Ravaud, and Guy Lemarquand, "Magnetic Field in MRI Yokeless Devices: Analytical Approach," Progress In Electromagnetics Research, Vol. 94, 327-341, 2009.
doi:10.2528/PIER09061205
References

1. Marble, A. E., "Strong, stray static magnetic fields," IEEE Trans. Magn., Vol. 44, No. 5, 576-580, 2008.
doi:10.1109/TMAG.2008.918278

2. Chang, W., K. Chen, and L. Hwang, "Single-sided mobile NMR with a halbach magnet," Magnetic Resonance Imaging, Vol. 2, No. 8, 1095-1102, 2006.
doi:10.1016/j.mri.2006.04.005

3. Leupold, H. A., E. Potenziani II, and M. G. Abele, "Applications of yokeless flux confinement," J. Appl. Phys., Vol. 64, No. 3, 1988.

4. Chen, J. and C. Xu, "An improved discrete configuration of a cylinder magnet for portable nuclear magnetic resonance instruments," J. Appl. Phys., Vol. 101, No. 2, 2007.

5. Ren, Z., D. Xie, and H. Li, "Study on shimming method for open permanent magnet of MRI," Progress In Electromagnetics Research M, Vol. 6, 23-24, 2009.
doi:10.2528/PIERM08122406

6. Shirai, T., T. Haishi, S. Utsuzawa, Y. Matsuda, and K. Kose, "Development of a compact mouse mri using a yokeless permanent magnet," Magnetic Resonance in Medical Sciences, Vol. 4, No. 3, 137-143, 2005.
doi:10.2463/mrms.4.137

7. Abele, M. and H. A. Leupold, "A general method for flux confinement in permanent magnet structure," J. Appl. Phys., Vol. 64, No. 10, 5988-5990, 1988.
doi:10.1063/1.342172

8. Abele, M., J. Jensen, and H. Rusine, "Generation of uniform high fields with magnetized wedges," IEEE Trans. Magn., Vol. 33, No. 5, 3874-3876, 1997.
doi:10.1109/20.619600

9. Li, C. and M. Devine, "E±ciency of permanent magnet assemblies for MRI devices," IEEE Trans. Magn., Vol. 41, No. 10, 3835-3837, 2005.
doi:10.1109/TMAG.2005.854982

10. Miyata, K., K. Ohashi, A. Muraoka, and N. Takahashi, "3-D magnetic field analysis of permanent-magnet type of MRI taking account of minor loop," IEEE Trans. Magn., Vol. 42, No. 4, 1451-1454, 2006.
doi:10.1109/TMAG.2006.871430

11. Podol'skii, A., "Development of permanent magnet assembly for MRI devices," IEEE Trans. Magn., Vol. 34, No. 1, 248-252, 1998.
doi:10.1109/20.650251

12. Marble, A. E., I. V. Mastikhui, B. G. Colpitts, and B. J. Balcom, "Designing static fields for unilateral magnetic resonance by a scalar potential approach," IEEE Trans. Magn., Vol. 43, No. 5, 1903-1911, 2007.
doi:10.1109/TMAG.2006.889538

13. Ryu, J. S., Y. Yao, C. S. Koh, and Y. J. Shin, "Development of permanent magnet assembly for MRI devices," IEEE Trans. Magn., Vol. 42, No. 4, 1351-1353, 2006.
doi:10.1109/TMAG.2006.871563

14. Takahashi, N., A. Muraoka, D. Miyagi, K. Miyata, and K. Okashi, "3-D FEM analysis of residual magnetism produced by x-gradient coil of permanent magnet type of MRI," IEEE Trans. Magn., Vol. 43, No. 4, 1809-1812, 2007.
doi:10.1109/TMAG.2007.892526

15. Sinha, G., R. Sandararaman, and G. Singh, "Design concepts of optimized MRI magnet," IEEE Trans. Magn., Vol. 44, No. 10, 2351-2360, 2008.
doi:10.1109/TMAG.2008.2001843

16. Thompson, M. R., R. W. Brown, and V. C. Srivastava, "An inverse approach to the design of MRI main magnets," IEEE Trans. Magn., Vol. 30, No. 1, 108-112, 1994.
doi:10.1109/20.272522

17. Halbach, K., "Strong rare earth cobalt quadrupoles," IEEE Trans. Magn., Vol. 26, No. 3, 3882-3884, 1979.

18. Ravaud, R. and G. Lemarquand, "Discussion about the magnetic field produced by cylindrical halbach structures," Progress In Electromagnetics Research B, Vol. 13, 275-308, 2009.
doi:10.2528/PIERB09012004

19. Babic, S. I., C. Akyel, and M. M. Gavrilovic, "Calculation improvement of 3D linear magnetostatic field based on fictitious magnetic surface charge," IEEE Trans. Magn., Vol. 36, No. 5, 3125-3127, 2000.
doi:10.1109/20.908707

20. Ravaud, R., G. Lemarquand, V. Lemarquand, and C. Depollier, "Analytical calculation of the magnetic field created by permanent-magnet rings," IEEE Trans. Magn., Vol. 44, No. 8, 1982-1989, 2008.
doi:10.1109/TMAG.2008.923096

21. Ravaud, R., G. Lemarquand, V. Lemarquand, and C. Depollier, "Discussion about the analytical calculation of the magnetic field created by permanent magnets," Progress In Electromagnetics Research B, Vol. 11, 281-297, 2009.
doi:10.2528/PIERB08112102

22. Ravaud, R., G. Lemarquand, V. Lemarquand, and C. Depollier, "The three exact components of the magnetic field created by a radially magnetized tile permanent magnet," Progress In Electromagnetics Research, Vol. 88, 307-319, 2008.
doi:10.2528/PIER08112708

22. Ravaud, R. and G. Lemarquand, "Analytical expression of the magnetic field created by tile permanent magnets tangentially magnetized and radial currents in massive disks," Progress In Electromagnetics Research B, Vol. 13, 309-328, 2009.
doi:10.2528/PIERB09012704

24. Ravaud, R., G. Lemarquand, V. Lemarquand, and C. Depollier, "Magnetic field produced by a tile permanent magnet whose polarization is both uniform and tangential," Progress In Electromagnetics Research B, Vol. 13, 1-20, 2009.
doi:10.2528/PIERB08121901