Quiet MRI with novel acoustic noise reduction

  • A. Katsunuma
  • H. Takamori
  • Y. Sakakura
  • Y. Hamamura
  • Y. Ogo
  • R. Katayama
Article

Abstract

Fast scan techniques, which are used to reduce scanning times, have raised scanning noise levels in magnetic resonance imaging (MRI) systems, resulting in greater patient discomfort and stress. It is well known that this noise is caused by vibration of the gradient coil due to the Lorentz forces generated by the current in the gradient coil, which is placed in a static magnetic field. We have confirmed that MRI noise can be substantially reduced by sealing the gradient coil in a vacuum chamber to block airborne vibration propagation, by supporting the gradient coil independently to block solid vibration propagation and by decreasing the eddy currents induced in RF coils, the RF shield and the static-field-magnet cryostat. Based on these findings, we have developed a silent MRI system in which scanning noise is markedly reduced under a wide range of scanning conditions.

Keywords

Silent technology Silent MRI Vacuum chamber Noise propagation 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    Hennel F, Girard F, Loenneker T. “Silent” MRI with soft gradient pulses. Magn Reson Mod 1999;42:6–10.CrossRefGoogle Scholar
  2. [2]
    Hedeen R. Edelstein W. Characterization and prediction of gradient acoustic noise in MR imagers. Magn Reson Med 1997;37:7–10.PubMedCrossRefGoogle Scholar
  3. [3]
    Foster J, Hall D, Summerfield A, Palmer A, Bowtell R. Sound-level measurements and calculations of safe noise dosage during EPI at 3 T. J Magn Reson Imaging 2000;12:157–63.PubMedCrossRefGoogle Scholar
  4. [4]
    Mcjury M. Shellock F. Auditory noise associated with MR procedures. J Magn Reson Imaging 2000;12:37–45.PubMedCrossRefGoogle Scholar
  5. [5]
    Mansfield P. Glover P, Beaumont J. Sound generation in gradient coil structures for MRI. Magn Reson Med 1998;39:539–50.PubMedCrossRefGoogle Scholar
  6. [6]
    Price D, De Wilde J, Papadaki A, Curran J, Kitney R. Investigation of acoustic noise on 15 MRI scanners from 0.2 T to 3 T. J Magn Reson Imaging 2001;13:288–93.PubMedCrossRefGoogle Scholar
  7. [7]
    Furukawa H. Magnetic resonance imaging apparatus. US Patent 5,489,848, 1995.Google Scholar
  8. [8]
    Pla FG. Low noise MRI scanner. US Patent 5,793,210, 1996.Google Scholar
  9. [9]
    Price D, Wilde J, Papadaki A, Curran J, Kitney R. Acoustic noise on 1.5 T MRI systems. Int Soc Magn Reson Med 2001:1763.Google Scholar
  10. [10]
    Lord Rayleigh. Theory of sound, vol. 2. New York: Dover. 1945, p. 3.Google Scholar
  11. [11]
    Hunt FV. American Institute of Physics handbook. New York: McGraw-Hill, 1957, p. 3–28.Google Scholar
  12. [12]
    Lamb H. Hydrodynamics. 6th ed. Cambridge, 1963, chap. 1.Google Scholar
  13. [13]
    Mansfield P. Chapman B. Active magnetic screening of gradient coils in NMR imaging. J Magn Reson 1986;66:573–6.Google Scholar
  14. [14]
    Chapman B, Mansfield P. Double active magnetic screening of coils in NMR. J Phys D: Appl Phys 1986;19:L129–31.CrossRefGoogle Scholar
  15. [15]
    Roemer PB, Hickley JS. Self-shielded gradient coils for nuclear magnetic resonance imaging. US Patent 4,737,716, 1986.Google Scholar
  16. [16]
    Turner R. A target field approach to optimal coil design. J Phys D: Appl Phys 1986; 19:L147–51.CrossRefGoogle Scholar
  17. [17]
    Shvartsman Sh, Brown R, Cheng Y. Eagan T. Fujita H, Morich M, et al. Application of the SUSHI method to the design of gradient coils. Magn Reson Med 2001;45:147–55.PubMedCrossRefGoogle Scholar

Copyright information

© Elsevier Science B.V 2002

Authors and Affiliations

  • A. Katsunuma
    • 1
  • H. Takamori
    • 1
  • Y. Sakakura
    • 1
  • Y. Hamamura
    • 1
  • Y. Ogo
    • 2
  • R. Katayama
    • 2
  1. 1.Toshiba Medical System CompanyTochigiJapan
  2. 2.Kurume UniversityFukuokaJapan

Personalised recommendations