Abstract
Magnetic field strength has always been an important parameter to consider for Magnetic Resonance Imaging (MRI). It is generally agreed that the Signal to Noise Ratio (SNR) is approximately proportional to magnetic field strength [1,2], although other more subtle effects, such as chemical shift dispersion and susceptibility, also scale with field strength and can cause problems for good anatomical imaging. However, it is no surprise to learn that the engineering challenges presented by the commercial construction of higher field MRI systems are formidable. This chapter is an opportunity to introduce these to a wider audience.
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11. References
Hoult DI, Richards RE. 1976. The signal-to-noise ratio of the nuclear magnetic resonance experiment. J Magn Reson 24:71–83.
Edelstein WA, Glover GH, Hardy CJ, Redington RW. 1986. The intrinsic signal-to-noise ratio in NMR imaging. Magn Reson Med 3(4):604–618.
Stehling MK, Turner R, Mansfield P. 1991. Echo planar imaging: magnetic resonance imaging in a fraction of a second. Science 254:43–50.
Pykett IL, Rzedzian RR. 1987. Instant Images of the body by magnetic resonance. Magn Reson Med 5(6):563–571.
Ogawa S, Tank DW, Menon R, Ellermann JM, Kim SG, Merkle H, Ugurbil K. 1992. Intrinsic signal changes accompanying sensory stimulation — functional brain mapping with magnetic resonance imaging. Proc Natl Acad Sci USA 89(13), 5951–5955.
Robitaille P-ML, Warner R, Jagadeesh J, Abduljalil AM, Kangarlu A, Burgess R, Yang YYL, Zhu H, Jiang Z, Bailey RE, Chung W, Somawiharja Y, Feenan P, Rayner DL. 1999. Design and assembly of an 8 Tesla whole-body MR scanner. J Comput Assist Tomogr 23(6):808–820.
Tkac I, Andersen P, Adriany G, Merkle H, Ugurbil K, Gruetter R. 2001. In-vivo 1H NMR spectroscopy of the human brain at 7T. Magn Reson Med 46(3):451–456.
Pfeuffer J, Adriany G, Shmuel A, Yacoub E, Van De Moortele PF, Hu X, Ugurbil K. 2002. Perfusion-based high-resolution functional imaging in the human brain at 7T. Magn Reson Med 47(5):903–911.
Wilson MN. 1998. Superconducting magnets. Oxford: Oxford UP.
de Graaf RA, Brown PB, McIntrye S, Rothman DL, Nixon TW. 2003. Dynamic shim updating (DSU) for multislice signal acquisition. Magn Reson Med 49(3):409–416.
Roopchansingh V, Jesmanowicz A, Hyde JS. 2004. Magnetic field homogeneity improvement in the lower frontal lobe by combined resistive and passive shims with a user-defined mask. Proc Int Soc Magn Reson Med 1650.
Wong EC, Mazaheri Y. 2004. Shimming of the inferior frontal cortex using an external local shim coil. Proc Int Soc Magn Reson Med 520.
Katsunuma A, Takamori H, Sakakura Y, Hamamura Y, Ogo Y, Katayama R. 2002. Quiet MRI with novel acoustic noise reduction. Magn Reson Mat Phys Biol Med 13:139–144.
Edelstein WA, Hedeen RA, Mallozzi RP, El Hamamsy SA, Ackermann RA, Havens TJ. 2002. Making MRI quieter. Magn Reson Imag 20:155–163.
Bowtell RW, Peters A. 1999. Analytic approach to the design of transverse gradient coils with co-axial return paths. Magn Reson Med 41:600–608.
Abduljalil AM, Aletras AH, Robitaille P-ML. 1997. Torque free asymmetric gradient coils for echo planar imaging. Magn Reson Med 31:450–453.
Hidalgo-Tobon SS, Bencsik M, Bowtell RW. 2004. Reduction of peripheral nerve stimulation via the use of combined gradient and uniform field coils. Proc Int Soc Magn Reson Med 11:659.
Asner FM. 1999. High-field superconducting magnets. Oxford: Oxford UP.
Restrictions on exposure to static and time-varying electromagnetic fields. 1995. National Radiological Protection Board, Chilton, Didcot, Oxon.
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Bird, J., Houlden, D., Kerley, N., Rayner, D., Simkin, D., Pittard, S. (2006). Design Considerations for Ultra High Field MRI Magnet Systems. In: Ultra High Field Magnetic Resonance Imaging. Biological Magnetic Resonance, vol 26. Springer, Boston, MA. https://doi.org/10.1007/978-0-387-49648-1_2
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DOI: https://doi.org/10.1007/978-0-387-49648-1_2
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