Advertisement

Toward Automated Manufacturing of RF Coils: Microstrip Resonators for 4.7 T Using 3D-Printed Dielectrics and Conductors

  • Saeed Javidmehr
  • Adam M. Maunder
  • Mojgan DaneshmandEmail author
  • Nicola De ZancheEmail author
Original Paper
  • 64 Downloads

Abstract

Microstrip transmission line (MTL) resonators are widely used as radio-frequency (RF) transceiver coils in high-field magnetic resonance imaging (MRI). Typically, discrete capacitors are used to tune the MTL resonators to the Larmor frequency and to match to the 50 Ω characteristic impedance of the RF chain. The cost, availability, and labor-intensive work of soldering capacitors on each coil contribute significantly to the expense of RF coil arrays for MRI; therefore, a manufacturing method with lower cost and fewer processing steps is desirable. The additive manufacturing method of rapid prototyping offers a new method to build custom-designed MTL resonators with reduced fabrication steps and, potentially, cost. This feasibility study explores fused deposition modelling to 3D print the MTL resonator structure simultaneously with matching/tuning capacitors and conductors. Typical low-cost 3D printers are capable of printing only polymers, not metal and polymer printing in one machine. In this work, a low-cost 3D printer was modified by adding the capability to print conductive ink and used to print MTL resonators with monolithic parallel-plate capacitors. These integrated capacitors eliminate the repetitive work of soldering, and tuning is achieved by trimming the capacitor plates. In addition, 3D printing allows unconventional designs that minimize the amount of dielectric below the microstrip and, therefore, losses in the substrate. Resulting signal-to-noise ratio values using ink conductors are within 30% of those achieved with copper despite a resistivity that is two orders of magnitude higher. This performance gap can be addressed using newer inks that have much lower resistivity.

Notes

Acknowledgements

The authors wish to acknowledge CMC Microsystems for software access and Machina Corp. for assistance with their 3D printer. We thank Peter Šereš for assistance with imaging measurements, and Sabreen Khan for proofreading. We also thank Mr. Herbert Dexel for assistance with setup of the pressure regulator and Evonik Inc. for providing the Rohacell foam.

Funding

This work was supported by the Canada Research Chairs Program and by the Natural Sciences and Engineering Research Council (Canada).

References

  1. 1.
    U. Katscher, P. Bornert, NMR Biomed. 19, 393–400 (2006)CrossRefGoogle Scholar
  2. 2.
    P. Vernickel, P. Röschmann, C. Findeklee, K.M. Lüdeke, C. Leussler, J. Overweg, U. Katscher, I. Grässlin, K. Schünemann, Magn. Reson. Med. 58, 381–389 (2007)CrossRefGoogle Scholar
  3. 3.
    Y. Pang, Z. Xie, D. Xu, D.A. Kelley, S.J. Nelson, D.B. Vigneron, X. Zhang, Magn. Reson. Imaging 30, 290–298 (2012)CrossRefGoogle Scholar
  4. 4.
    X. Zhang, X.H. Zhu, W. Chen, Magn. Reson. Med. 53, 1234–1239 (2005)CrossRefGoogle Scholar
  5. 5.
    Z. Xiaoliang, K. Ugurbil, R. Sainati, C. Wei, IEEE Trans. Biomed. Eng. 52, 495–504 (2005)CrossRefGoogle Scholar
  6. 6.
    B. Wu, C. Wang, J. Lu, Y. Pang, S.J. Nelson, D.B. Vigneron, X. Zhang, IEEE Trans. Med. Imaging 31, 183–191 (2012)CrossRefGoogle Scholar
  7. 7.
    X. Zhang, Y. Liao, X.-H. Zhu, W. Chen, Proc. Intl. Soc. Magn. Reson. Med. 11, 1602 (2004)Google Scholar
  8. 8.
    D.O. Brunner, N.D. Zanche, J. Froehlich, D. Baumann, K.P. Pruessmann, Proc. Intl. Soc. Magn. Reson. Med. 15, 448 (2007)Google Scholar
  9. 9.
    X. Zhang, K. Ugurbil, W. Chen, J. Magn. Reson. 161, 242–251 (2003)ADSCrossRefGoogle Scholar
  10. 10.
    G. Adriany, E.J. Auerbach, C.J. Snyder, A. Gözübüyük, S. Moeller, J. Ritter, P-F. van de Moortele, T. Vaughan, K. Uğurbil, Magn. Reson. Med. 63, 1478–1485 (2010)CrossRefGoogle Scholar
  11. 11.
    G. Adriany, P.F. Van de Moortele, F. Wiesinger, S. Moeller, J.P. Strupp, P. Andersen, C. Snyder, X. Zhang, W. Chen, K.P. Pruessmann, P. Boesiger, T. Vaughan, K. Uğurbil, Magn. Reson. Med. 53, 434–445 (2005)CrossRefGoogle Scholar
  12. 12.
    R.F. Lee, C.R. Westgate, R.G. Weiss, D.C. Newman, P.A. Bottomley, Magn. Reson. Med. 45, 673–683 (2001)CrossRefGoogle Scholar
  13. 13.
    M. Ahmadloo, P. Mousavi, in: Proceedings of the IEEE Antennas and Propagation Society International Symposium, pp. 780-781 (2013)Google Scholar
  14. 14.
    Y. Seo, Concepts Magn. Reson. Part B Magn. Reson. Eng. 41B, 111–119 (2012)ADSCrossRefGoogle Scholar
  15. 15.
    K.H. Herrmann, C. Gartner, D. Gullmar, M. Kramer, J.R. Reichenbach, Med. Eng. Phys. 36, 1373–1380 (2014)CrossRefGoogle Scholar
  16. 16.
    J. Mispelter, M. Lupu, A. Briguet, NMR Probeheads for Biophysical and Biomedical Experiments: Theoretical Principles and Practical Guidelines (Imperial College Press, London, 2006)CrossRefGoogle Scholar
  17. 17.
    Q.X. Yang, W. Luo, S. Rupprecht, Z. Herse, C. Sica, J. Wang, Z. Cao, J. Vesek, M.T. Lanagan, G. Carluccio, Y.C. Ryu, C.M. Collins, J. Magn. Reson. Imaging 38, 435–440 (2013)CrossRefGoogle Scholar
  18. 18.
    T. Nakagawa, T. Nakiri, R. Hosoya, Y. Tajitsu, IEEE Trans. Ind. Appl. 40, 1020–1024 (2004)CrossRefGoogle Scholar
  19. 19.
    S.J. Park, F.L. Jin, Polym. Int. 54, 705–709 (2004)CrossRefGoogle Scholar
  20. 20.
    J. Rumble, Handbook of Chemistry and Physics (CRC Press, Boca Raton, 2017)Google Scholar
  21. 21.
    J.G. Och, G.D. Clarke, W.T. Sobol, C.W. Rosen, S.K. Mun, Med. Phys. 19, 217–229 (1992)CrossRefGoogle Scholar
  22. 22.
    H. Heuermann, in: IEEE International Microwave Symposium Digest, pp. 1815-1818 (2003)Google Scholar
  23. 23.
    A. Yahya, N. De Zanche, P.S. Allen, NMR Biomed. 26, 533–541 (2013)CrossRefGoogle Scholar
  24. 24.
    W.A. Edelstein, G.H. Glover, C.J. Hardy, R.W. Redington, Magn. Reson. Med. 3, 604–618 (1986)CrossRefGoogle Scholar
  25. 25.
    P. Mansfield, P. Morris, NMR Imaging in Biomedicine (Academic Press, Cambridge, 1982)Google Scholar
  26. 26.
    A.R. Horch, J.C. Gore, Proc. Intl. Soc. Magn. Reson. Med. 23, 853 (2015)Google Scholar
  27. 27.
    A.R. Horch, J.C. Gore, Proc. Intl. Soc. Magn. Reson. Med. 24, 2147 (2016)Google Scholar

Copyright information

© Springer-Verlag GmbH Austria, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Electrical and Computer EngineeringUniversity of Alberta, DICE 11-324EdmontonCanada
  2. 2.Department of Medical PhysicsAlberta Health Services, Cross Cancer InstituteEdmontonCanada
  3. 3.Division of Medical Physics, Department of OncologyUniversity of AlbertaEdmontonCanada

Personalised recommendations