Calculations ofB 1 distribution, specific energy absorption rate, and intrinsic signal-to-noise ratio for a body-size birdcage coil loaded with different human subjects at 64 and 128 MHz

  • W. Liu
  • C. M. Collins
  • M. B. Smith


A numerical model of a female body is developed to study the effects of different body types with different coil drive methods on radio-frequency magnetic (B 1) field distribution, specific energy absorption rate (SAR), and intrinsic signal-to-noise ratio (ISNR) for a body-size birdcage coil at 64 and 128 MHz. The coil is loaded with either a larger, more muscular male body model (subject 1) or a newly developed female body model (subject 2), and driven with-two-port (quadrature), four-port, or many (ideal) sources. Loading the coil with subject 1 results in significantly less homogeneousB 1 field, higher SAR, and lower ISNR than those for subject 2 at both frequencies. This dependence of MR performance and safety measures on body type indicates a need for a variety of numerical models representative of a diverse population for future calculations. The different drive methods result in similarB 1 field patterns, SAR, and ISNR in all cases.


Flip Angle Body Model Finite Difference Time Domain Finite Difference Time Domain Method Birdcage Coil 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    Bottomley P.A., Andrew E.: Phys. Med. Biol.23, 630–643 (1978)CrossRefGoogle Scholar
  2. 2.
    Bottomley P.A., Redington R.W., Edelstein W.A., Schenck J.F.: Magn. Reson. Med.2, 336–349 (1985)CrossRefGoogle Scholar
  3. 3.
    Hoult D., Lauterbur P.: J. Magn. Reson.34, 425–433 (1979)Google Scholar
  4. 4.
    Chen C.-N., Sank V., Cohen S., Hoult D.: Magn. Reson. Med.3, 722–729 (1986)CrossRefGoogle Scholar
  5. 5.
    Glover G.H., Hayes C.E., Pelc N.J., Edelstein W.A., Mueller O.M., Hart H.R., Hardy C.J., O’Donnell M., Barber W.D.: J. Magn. Reson.64, 255–270 (1985)Google Scholar
  6. 6.
    Edelstein W., Glover G.H., Hardy C., Redington R.W.: Magn. Reson. Med.3, 604–618 (1986)CrossRefGoogle Scholar
  7. 7.
    Carlson J.: Magn. Reson. Med.10, 399–403 (1989)CrossRefGoogle Scholar
  8. 8.
    Grandolfo M., Vecchia P., Gandhi O.: Biolectromagnetics11, 117–128 (1990)CrossRefGoogle Scholar
  9. 9.
    Wen H., Denison T., Singerman R., Balaban R.: J. Magn. Reson.125, 65–71 (1997)CrossRefADSGoogle Scholar
  10. 10.
    Singerman R.W., Denison T.J., Wen H., Balaban R.S.: J. Magn. Reson.125, 72–83 (1997)CrossRefADSGoogle Scholar
  11. 11.
    Gandhi O., Chen X.: Magn. Reson. Med.41, 816–823 (1999)CrossRefGoogle Scholar
  12. 12.
    Yee K.S.: IEEE Trans. Antennas Propag.14, 302–307 (1966)MATHCrossRefADSGoogle Scholar
  13. 13.
    Kunz K.S., Luebbers R.J.: The Finite Difference Time Domain Method for Electromagnetics. Ann Arbor: CRC 1993.Google Scholar
  14. 14.
    Collins C.M., Smith M.B.: Magn. Reson. Med.45, 692–699 (2001)CrossRefGoogle Scholar
  15. 15.
    Hayes C.E., Edelstein W.A., Schenck J.F., Mueller O.M., Eash M.: J. Magn. Reson.63, 622–628 (1985)Google Scholar
  16. 16.
    Ledden P.J., Wald L.L., Vaughan, J.T., in: Proceedings of the Eighth Scientific Meeting of the International Society for Magnetic Resonance in Medicine, April 1–7, 2000, Denver, Colorado, USA (Moonen C.T., ed.), p. 1395. Denver, CO: ISMRM 2000.Google Scholar
  17. 17.
    Ibrahim T.S., Lee R., Baertlein B.A., Kangarlu A., Robitaille P.M.L.: Magn. Reson. Imaging18, 733–742 (2000)CrossRefGoogle Scholar
  18. 18.
    Collins C.M., Li S., Smith M.B.: Magn. Reson. Med.40, 847–856 (1998)CrossRefGoogle Scholar
  19. 19.
    Collins C.M.: Calculations of RF Magnetic Fields and SAR Experienced by the Human Body during MRI, p. 200. Philadelphia, Pa.: University of Pennsylvania 1999.Google Scholar
  20. 20.
    Gabriel C.: Compilation of the Dielectric Properties of Body Tissues at RF and Microwave Frequencies. Report AL/OE-TR-1996-0037. Brooks Air Force Base, Texas: Air Force Material Command 1996.Google Scholar
  21. 21.
    Erdman W.S., Gos, T.: J. Biomech.23, 945–947 (1990)CrossRefGoogle Scholar
  22. 22.
    Huang H.K., Wu S.C.: Comput. Biol. Med.6, 337–343 (1976)CrossRefGoogle Scholar
  23. 23.
    Cho Z.H., Tsai C.M., Wilson G.: Phys. Med. Biol.20, 879–889 (1975)CrossRefGoogle Scholar
  24. 24.
    Clauser, C.E., McConville J.T., Young J.W.: Weight, Volume, and Center of Mass of Segments of the Human Body. Report AMRL-TR-69-70. Wright-Patterson Air Force Base, Ohio: Aerospace Medical Research Laboratory 1969.Google Scholar
  25. 25.
    Collins C.M., Smith M.B.: J. Magn. Reson. Imaging18, 383–388 (2003)CrossRefGoogle Scholar
  26. 26.
    McKinnon G., Wang Z. in: Proceedings of the 11th Scientific Meeting of the International Society for Magnetic Resonance in Medicine, July 10–16, 2003, Toronto, Ontario, Canada (Lomas D.J., ed.), p. 2381. Toronto, Ontario: ISMRM 2003.Google Scholar
  27. 27.
    Alecci M., Collins C.M., Smith M.B., Jezzard P.: Magn. Reson. Med.46, 379–385 (2001)CrossRefGoogle Scholar
  28. 28.
    Liao Z.P., Wong H.L., Yang G.P., Yuan Y.F.: Sci. Sin. A27, 1063–1076 (1984)MATHGoogle Scholar
  29. 29.
    Collins C.M., Smith M.B.: Magn. Reson. Med.45, 684–691 (2001)CrossRefGoogle Scholar
  30. 30.
    Hoult D.I.: Concepts Magn. Reson.12, 173–187 (2000)CrossRefGoogle Scholar
  31. 31.
    Duck F.A.: Physical Properties of Tissue — A Comprehensive Reference Book. New York: Academic Press 1990.Google Scholar
  32. 32.
    Vaughan J.T., Garwood M., Collins C.M., Liu W., DelaBarre L., Adriany G., Andersen P., Merkle H., Goebel R., Smith M.B., Uĝurbil K.: Magn. Reson. Med.46, 24–30 (2001)CrossRefGoogle Scholar
  33. 33.
    Caputa K., Okeniewski M., Stuchly M.A.: IEEE Antennas Propag. Mag.41, 102–107 (1999)CrossRefADSGoogle Scholar
  34. 34.
    Jin J., Shen G., Perkins T.: Magn. Reson. Med.32, 418–422 (1994)CrossRefGoogle Scholar
  35. 35.
    Zhai Z., DeMeester G.D., Shvartsman S.M., Morich M.A. in: Proceedings of the 10th Scientific Meeting of the International Society for Magnetic Resonance in Medicine, May 18–24, 2002, Honolulu, Hawaii, USA (Evelhoch J.Z., ed.), p. 773. Honolulu, Hawaii, USA: ISMRM 2002.Google Scholar
  36. 36.
    International Electrotechnical Commission: Medical electrical equipment part 2–33: Particular requirements for the safety of magnetic resonance equipment for medical diagnosis. Reference nr IEC 60601 1-2-33:2002(E). Geneva: International Electrotechnical Commission 2002.Google Scholar

Copyright information

© Springer 2005

Authors and Affiliations

  • W. Liu
    • 1
  • C. M. Collins
    • 1
  • M. B. Smith
    • 1
    • 2
  1. 1.Center for NMR Research, NMR/MRI Building, Department of Radiology H066The Pennsylvania State University College of MedicineHersheyUSA
  2. 2.Department of Cellular and Molecular PhysiologyPennsylvania State University College of MedicineHersheyUSA

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