Design, Simulation, Modeling, and Implementation of a Square Helmholtz Coil in Contrast with a Circular Coil for MRI Applications

S. M. A. Ghaly, M. O. Khan

Abstract


This paper focuses on Helmholtz-type coils that can produce a second-order homogeneity field to be used for Magnetic Resonance Imaging (MRI) applications. A Helmholtz coil is a device used for producing a region of a nearly uniform magnetic field. It consists of two identical magnetic coils that are placed symmetrically along a common axis, one on either side of the experimental area, separated by a distance equal to the radius of the circular coil and half-length of the side of the square coils. Each coil carries an equal electrical current flowing in the same direction. The main objective of this article is to calculate the magnetic field provided by the coils at any point in space and to show and compare the uniform magnetic field induced by the square and circular Helmholtz coils. With the aid of MATLAB simulation tool, mathematical equations are simulated to demonstrate the axial magnetic field produced by one and two loops. Also, the design and simulation of electrical modeling for square and circular Helmholtz coils are performed using PSPICE. Finally, these coils are realized and tested experimentally, and the results for square and circular Helmholtz coils are compared.


Keywords


square and circular Helmholtz coil; radiofrequency coils; modeling; simulation; MATLAB; PSPICE; electromagnetic field measurement; impedance measurements; MRI

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References


F. Romeo, D. I. Hoult, “Magnet field profiling: analysis and correcting coil design”, Magnetic Resonance in Medicine, Vol. 1, No. 1, pp. 44-65, 1984

C. E. Hayes, W. A. Edelstein, J. F. Schenck, O. M. Mueller, M. Eash, “An efficient, highly homogeneous radiofrequency coil for whole-body NMR imaging at 1.5 T”, Journal of Magnetic Resonance, Vol. 63, pp. 622-628, 1985

L. Guendouz, S. M. A. Ghaly, A. Hedjiedj, J. M. Escanye, D. Canet, “Improved Helmholtz-type magnetic resonance imaging coils with high-B1 homogeneity-spherical and ellipsoidal four-coil systems”, Concepts in Magnetic Resonance, Vol. 33B, No. 1, pp. 9-20, 2008

K. Asher, N. K. Bangerter, R. D. Watkins, G. E. Gold, “Radiofrequency coils for musculoskeletal MRI”, Topics in Magnetic Resonance Imaging, Vol. 21, No. 5, pp. 315–323, 2010

S. M. A. Ghaly, L. Guendouz, A. Hedjiedj, J. M. Escanye, D. Canet, “Improved Helmholtz-type coils with high B1 homogeneity-spherical and ellipsoidal configurations”, 24th IASTED International Multi-Conference on Biomedical Engineering, Innsbruck, Austria, February 15-17, 2006

S. Li, Q. X. Yang, M. B. Smith, “RF coil optimization: Evaluation of B1 field homogeneity using field histograms and finite element calculations”, Magnetic Resonance Imaging, Vol. 12, No. 7, pp. 1079-1087, 1994

B. Gruber, M. Froeling, T. Leiner, D. W. J. Klomp, “RF coils: A practical guide for nonphysicists”, Journal of Magnetic Resonance, Vol. 48, No. 3, pp. 590–604, 2018

J. Mispelter, M. Lupu, A. Briguet, NMR probeheads for biophysical and biomedical experiments, theoretical principles & practical guidelines, 1st edition, Imperial College Press, 2006

B. J. Dardzinski, S. Li, C. M. Collins, G. D. Williams, M. B. Smith, “A birdcage coil tuned by RF shielding for application at 9.4 T”, Journal of Magnetic Resonance, Vol. 131, No. 1, pp. 32-38, 1998

S. M. A. Ghaly, S. A. Sowayan, “A high B1 field homogeneity generation using free element elliptical four-coil system”, American Journal of Applied Sciences, Vol. 11, No. 4, pp. 534-540, 2014

S. M. A. Ghaly, K. A. A. Snaie, S. S. A. Sowayan, “Design and testing of radiofrequency spherical four coils”, Modern Applied Science, Vol. 10, No. 5, pp. 186-193, 2016

S. M. A. Ghaly, K. A. A. Snaie, O. K. Mohammad, “Spherical and improved Helmholtz coil with high B1 homogeneity for magnetic resonance imaging”, American Journal of Applied Sciences, Vol. 13, No. 12, pp. 1413-1418, 2016

S. M. A. Ghaly, K. A. A. Snaie, A. M. Ali, “Design and modeling of a radiofrequency coil derived from a Helmholtz structure”, Engineering, Technology & Applied Science Research, Vol. 9, No. 2, pp. 4037-4040, 2019

M. Decorps, P. Blondet, H. Reutenauer, J. P. Albrand, C. Remy, “An inductively coupled, series-tuned NMR probe”, Journal of Magnetic Resonance, Vol. 65, No. 1, pp. 100-109, 1985

J. M. Boesch, A. P. Koretsky, “An in vivo NMR probe circuit for improved sensitivity”, Journal of Magnetic Resonance, Vol. 54, No. 3, pp. 526-532, 2003

F. Alorifi, S. M. A. Ghaly, M. Shalaby, M. A. Ali, M. O. Khan, “Analysis and detection of a target gas system based on TDLAS & labVIEW”, Engineering, Technology & Applied Science Research, Vol. 9, No. 3, pp. 4196-4199, 2019

S. M. A. Ghaly, “LabVIEW based implementation of resistive temperature detector linearization techniques”, Engineering, Technology & Applied Science Research, Vol. 9, No. 4, pp. 4530-4533, 2019

S. M. A. Ghaly, M. O. Khan, S. O. E. Mehdi, M. A. Awad, Μ. A. Ali, K. A. A. Snaie, “Implementation of a broad range smart temperature measurement system using auto-selected multi-sensor core in labVIEW environment”, Engineering, Technology & Applied Science Research, Vol. 9, No. 4, pp. 4511-4515, 2019

D. M. Ginsberg, M. J. Melchner, “Optimum geometry of saddle shaped coils for generating a uniform magnetic field”, Review of Scientific Instruments, Vol. 41, No. 1, pp. 122-123, 2010

H. Fujita, T. Zheng, X. Yang, M. J. Finnerty, S. Handa, “RF surface receive array coils: The art of an LC circuit”, Journal of Magnetic Resonance Imaging, Vol. 38, No. 1, pp. 12–25, 2013




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