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Portable Low-Cost MRI System Based on Permanent Magnets/Magnet Arrays

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초록

Portable low-cost magnetic resonance imaging (MRI) systems have the potential to enable “point-of-care” and timely MRI diagnosis, and to make this imaging modality available to routine scans and to people in underdeveloped countries and areas. With simplicity, no maintenance, no power consumption, and low cost, permanent magnets/magnet arrays/magnet assemblies are attractive to be used as a source of static magnetic field to realize the portability and to lower the cost for an MRI scanner. However, when taking the canonical Fourier imaging approach and using linear gradient fields, homogeneous fields are required in a scanner, resulting in the facts that either a bulky magnet/magnet array is needed, or the imaging volume is too small to image an organ if the magnet/magnet array is scaled down to a portable size. Recently, with the progress on image reconstruction based on nonlinear gradient field, static field patterns without spatial linearity can be used as spatial encoding magnetic fields (SEMs) to encode MRI signals for imaging. As a result, the requirements for the homogeneity of the static field can be relaxed, which allows permanent magnets/magnet arrays with reduced sizes, reduced weight to image a bigger volume covering organs such as a head. It offers opportunities of constructing a truly portable low-cost MRI scanner. For this exciting potential application, permanent magnets/magnet arrays have attracted increased attention recently. A magnet/magnet array is strongly associated with the imaging volume of an MRI scanner, image reconstruction methods, and RF excitation and RF coils, etc. through field patterns and field homogeneity. This paper offers a review of permanent magnets and magnet arrays of different kinds, especially those that can be used for spatial encoding towards the development of a portable and low-cost MRI system. It is aimed to familiarize the readers with relevant knowledge, literature, and the latest updates of the development on permanent magnets and magnet arrays for MRI. Perspectives on and challenges of using a permanent magnet/magnet array to supply a patterned static magnetic field, which does not have spatial linearity nor high field homogeneity, for image reconstruction in a portable setup are discussed.

Abstract

Portable low-cost magnetic resonance imaging (MRI) systems have the potential to enable “point-of-care” and timely MRI diagnosis, and to make this imaging modality available to routine scans and to people in underdeveloped countries and areas. With simplicity, no maintenance, no power consumption, and low cost, permanent magnets/magnet arrays/magnet assemblies are attractive to be used as a source of static magnetic field to realize the portability and to lower the cost for an MRI scanner. However, when taking the canonical Fourier imaging approach and using linear gradient fields, homogeneous fields are required in a scanner, resulting in the facts that either a bulky magnet/magnet array is needed, or the imaging volume is too small to image an organ if the magnet/magnet array is scaled down to a portable size. Recently, with the progress on image reconstruction based on nonlinear gradient field, static field patterns without spatial linearity can be used as spatial encoding magnetic fields (SEMs) to encode MRI signals for imaging. As a result, the requirements for the homogeneity of the static field can be relaxed, which allows permanent magnets/magnet arrays with reduced sizes, reduced weight to image a bigger volume covering organs such as a head. It offers opportunities of constructing a truly portable low-cost MRI scanner. For this exciting potential application, permanent magnets/magnet arrays have attracted increased attention recently. A magnet/magnet array is strongly associated with the imaging volume of an MRI scanner, image reconstruction methods, and RF excitation and RF coils, etc. through field patterns and field homogeneity. This paper offers a review of permanent magnets and magnet arrays of different kinds, especially those that can be used for spatial encoding towards the development of a portable and low-cost MRI system. It is aimed to familiarize the readers with relevant knowledge, literature, and the latest updates of the development on permanent magnets and magnet arrays for MRI. Perspectives on and challenges of using a permanent magnet/magnet array to supply a patterned static magnetic field, which does not have spatial linearity nor high field homogeneity, for image reconstruction in a portable setup are discussed.

참고문헌 (76)

  1. Nishimura DG, "Principles of magnetic resonance imaging", pp.2010
  2. Pissanetzky S, "Structured coil electromagnets for magnetic resonance imaging and method for fabricating the same", US5382904, ~ (1995)
  3. Vaughan JT, "Progress toward a portable MRI system for human brain imaging", 24th ISMRM, pp.0498~ (2016)
  4. Esparza-Coss E, "A low cost MR", permanent magnet prototype, 1998, 440~
  5. Sarracanie M, "Low-cost high-performance MRI", Sci Rep, 5, pp.15177~ (2015)
  6. Morgan PS, "Design of uniform field biplanar magnets", 5th Meeting of ISMRM, pp.1447~ (1997)
  7. Hennig J, "Parallel imaging in non-bijective, curvilinear magnetic field gradients: a concept study", MAGMA, 21, pp.5~14 (2008)
  8. Schultz G, "Reconstruction of MRI data encoded with arbitrarily shaped, curvilinear, nonbijective magnetic fields", Magn Reson Med, 64, pp.1390~1403 (2010)
  9. Schultz G, "Radial imaging with multipolar magnetic encoding fields", IEEE Trans Med Imaging, 30, pp.2134~2145 (2011)
  10. Stockmann JP, "In vivo O-space imaging with a dedicated 12cm Z2 insert coil on a human 3T scanner using phase map calibration", Magn Reson Med, 69, pp.444~455 (2013)
  11. Stockmann JP, "O-space imaging: highly efficient parallel imaging using second-order nonlinear fields as encoding gradients with no phase encoding", Magn Reson Med, 64, pp.447~456 (2010)
  12. Cooley CZ, "Twodimensional imaging in a lightweight portable MRI scanner without gradient coils", Magn Reson Med, 73, pp.872~883 (2015)
  13. Ren ZH, "Magnet array for a portable magnetic resonance imaging system in RF and wireless technologies for biomedical and healthcare applications (IMWS-BIO)", 2015 IEEE MTT-S 2015 International Microwave Workshop Series, pp.92~95 (2015)
  14. Ren ZH, "A new yokeless permanent magnet array with high field strength and high field homogeneity for low-field portable MRI system", Joint Annual Meeting ISMRM-ESMRMB, pp.1743~ (2018)
  15. Leupold HA, "Adjustable multitesla permanent magnet field sources", IEEE Trans Magn, 29, pp.2902~2904 (1993)
  16. Sagawa M, "New material for permanent magnets on a base of Nd and Fe (invited)", J Appl Phys, 55, pp.2083~2087 (1984)
  17. Glover PM, "A novel gradient permanent magnet for profiling of planar films and coatings", J Magn Reson, 139, pp.90~97 (1999)
  18. Doughty D, "NMR in chemical engineering", pp.89~107 (2006), Wiley-VCH
  19. Bennett G, "Magnetic resonance profiling studies of the drying of filmforming aqueous dispersions and glue layers", Magn Reson Imaging, 21, pp.235~241 (2003)
  20. Wright SM, "A desktop magnetic resonance imaging system", MAGMA, 13, pp.177~185 (2002)
  21. Nagata A, "Development of an outdoor MRI system for measuring flow in a living tree", J Magn Reson, 265, pp.129~138 (2016)
  22. Terada Y, "Improved reliability in skeletal age assessment using a pediatric hand MR scanner with a 0.3T permanent magnet", Magn Reson Med Sci, 13, pp.215~219 (2014)
  23. Chang WH, "Single-sided mobile NMR with a Halbach magnet", Magn Reson Imaging, 24, pp.1095~1102 (2006)
  24. Moresi G, "Miniature permanent magnet for tabletop NMR", Conc Magn Reson, B19, pp.35~43 (2003)
  25. Zhu ZQ, "Halbach permanent magnet machines and applications: a review", IEE Proc Elec Power Appl, 148, pp.299~308 (2001)
  26. Abele MG, "Structures of permanent magnets" (1993), John Wiley & Sons Inc
  27. Mallinson JC, "One-Sided Fluxes - A Magnetic Curiosity?", IEEE Trans Magn, 9, pp.678~682 (1973)
  28. Halbach K, "Strong rare earth cobalt quadrupoles", IEEE Trans Nucl Sci, 26, pp.3882~3884 (1979)
  29. Halbach K, "Design of permanent multipole magnets with oriented rare earth cobalt material", Nuclear Instruments and Methods, 169, pp.1~10 (1980)
  30. Schneiderman J, "Diagnosis of thin fibrous cap atheromas by a self-contained intravascular magnetic resonance imaging probe in exvivo human aortas and in-situ coronary arteries", J Am Coll Cardiol, 45, pp.1961~1969 (2005)
  31. Atallah K, "The application of Halbach cylinders to brushless AC servo motors", IEEE Trans Magn, 34, pp.2060~2062 (1998)
  32. Zhu ZQ, "Analysis of anisotropic bonded NdFeB Halbach cylinders accounting for partial powder alignment", IEEE Trans Magn, 36, pp.3575~3577 (2000)
  33. Zhu ZQ, "Powder alignment system for anisotropic bonded NdFeB Halbach cylinders", IEEE Trans Magn, 36, pp.3349~3352 (2000)
  34. Raich HP, "Design and construction of a dipolar halbach array with a homogeneous field from identical bar magnets: NMR Mandhalas", Concepts Magn Reson, 23B, pp.16~25 (2004)
  35. Danieli E, "Mobile sensor for high resolution NMR spectroscopy and imaging", J Magn Reson, 198, pp.80~87 (2009)
  36. Phuc HD, "Design and construction of light weight portable NMR Halbach magnet. International journal on smart sensing and intelligent systems", International Journal on Smart Sensing and Intelligent Systems, 7, pp.1555~1578 (2014)
  37. Jackson JA, "Remote (inside-out)NMR. III. Detection of nuclear magnetic resonance in a remotely produced region of homogeneous magnetic field", J Magn Reson, 41, pp.411~421 (1980)
  38. Kleinberg R, "Novel NMR apparatus for investigating an external sample", J Magn Reson, 97, pp.466~485 (1992)
  39. Blank A, "Miniature selfcontained intravascular magnetic resonance (IVMI) probe for clinical applications", Magn Reson Med, 54, pp.105~112 (2005)
  40. Manz B, "A mobile one-sided NMR sensor with a homogeneous magnetic field: the NMRMOLE", J Magn Reson, 183, pp.25~31 (2006)
  41. Eidmann G, "The NMR MOUSE, a mibile universal surface explorer", J Magn Reson, Series A, 122, pp.104~109 (1996)
  42. Landeghem MV, "Low-gradient single-sided NMR sensor for one-shot profiling of human skin", J Magn Reson, 215, pp.74~84 (2012)
  43. Marble AE, "An analytical methodology for magnetic field control in unilateral NMR", J Magn Reson, 174, pp.78~87 (2005)
  44. Perlo J, "Profiles with microscopic resolution by single-sided NMR", J Magn Reson, 176, pp.64~70 (2005)
  45. Perlo J, "Ex situ NMR in highly homogeneous fields: 1H spectroscopy", Science, 315, pp.1110~1112 (2007)
  46. McDaniel P, "A 6.3kg singlesided magnet for 3D, point-of-care brain imaging", ISMRMESMRMB 2018, pp.0943~ (2018)
  47. Nishino E, "Permanent magnet array for magnetic medical appliance", Gee Co, London, U.K., Tech. Rep. GB 2112645 A, ~ (1983)
  48. Miyajima T, "Permanent magnet apparatus", Japanese Patent 60 210 804 A, ~ (1985)
  49. Aubert G, "Permanent magnet for nuclear magnetic resonance imaging equipment", US5332971A, ~ (1994)
  50. Kaczmarz S, "Angeneaherte aufloesung von systemen linearer gleichungen", Bull Acad Polon Sci Lett A, 35, pp.355~357 (1937)
  51. Lu D, "A TSVD-based approach for flexible spatial encoding strategy in portable magnetic resonance imaging (MRI) system", Special session on Electromagnetics at the Heart of the Magnetic Resonance Imaging (MRI). PIETS 2017 Singapore (2017)
  52. Ren ZH, "Magnet array for a portable magnetic resonance imaging system in RF and Wireless Technologies for Biomedical and Healthcare Applications (IMWS-BIO)", 2015 IEEE MTT-S 2015 International Microwave Workshop Series on. Taiwan, pp.92~95 (2015)
  53. Cooley CZ, "Design of sparse Halbach magnet arrays for portable mri using a genetic algorithm", IEEE Trans Magn, 54, pp.5100112~ (2018)
  54. Hugon C, "Design, fabrication and evaluation of a low-cost homogeneous portable permanent magnet for NMR and MRI", Comptes Rendus Chimie, 13, pp.388~393 (2010)
  55. Aubert G, "Cylindrical permanent magnet with longitudinal induced field", US5014032A, ~ (1991)
  56. Ren ZH, "A new yokeless permanent magnet array with high field strength and high field homogeneity for low-field portable MRI system", Joint Annual Meeting ISMRM-ESMRMB, pp.1743~ (2018)
  57. Ren ZH, "Design and optimization of a ring-pair permanent magnet array for head imaging in a low-field portable MRI system", IEEE Trans Magn, 55, pp.5100108~ (2018)
  58. Kim SH, "Temperature compensation of NdFeB permanent magnets", Proceedings of the 1997Particle Accelerator Conference, 3, pp.3227~3229 (1997)
  59. Rajagopal KR, "Novel methods of temperature compensation for permanent magnet sensors and actuators", IEEE Trans Magn, 37, pp.1995~1997 (2001)
  60. Danieli E, "Highly stable and finely tuned magnetic fields generated by permanent magnet assemblies", Phys Rev Lett, 110, pp.180801~ (2013)
  61. Watkins RD, "Temperature compensated NMR magnet and method of operation therefor", US6252405B1, ~ (2001)
  62. Schmidt R, "Flexible and compact hybrid metasurfaces for enhanced ultra high field in vivo magnetic resonance imaging", Sci Rep, 10, pp.1678~ (2017)
  63. Motovilova E, "Hilbert-curve-based metasurface to enhance sensitivity of radiofrequency coils for 7 T MRI", IEEE Trans Microw Theory Tech, 67, pp.615~625 (2019)
  64. Idiyatullin D, "Continuous SWIFT", J Magn Reson, 220, pp.26~31 (2012)
  65. Sohn SM, "In vivo MR imaging with simultaneous RF transmission and reception", Magn Reson Med, 76, pp.1932~1938 (2016)
  66. Chen X, "Computational methods for electromagnetic inverse scattering" (2018), Wiley-IEEE Press
  67. Leupold H, "Novel high-field permanentmagnet flux sources", IEEE Trans Magn, 23, pp.3628~3629 (1987)

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