Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Travelling-wave nuclear magnetic resonance


Nuclear magnetic resonance1,2 (NMR) is one of the most versatile experimental methods in chemistry, physics and biology3, providing insight into the structure and dynamics of matter at the molecular scale. Its imaging variant—magnetic resonance imaging4,5 (MRI)—is widely used to examine the anatomy, physiology and metabolism of the human body. NMR signal detection is traditionally based on Faraday induction6 in one or multiple radio-frequency resonators7,8,9,10 that are brought into close proximity with the sample. Alternative principles involving structured-material flux guides11, superconducting quantum interference devices12, atomic magnetometers13, Hall probes14 or magnetoresistive elements15 have been explored. However, a common feature of all NMR implementations until now is that they rely on close coupling between the detector and the object under investigation. Here we show that NMR can also be excited and detected by long-range interaction, relying on travelling radio-frequency waves sent and received by an antenna. One benefit of this approach is more uniform coverage of samples that are larger than the wavelength of the NMR signal—an important current issue in MRI of humans at very high magnetic fields. By allowing a significant distance between the probe and the sample, travelling-wave interaction also introduces new possibilities in the design of NMR experiments and systems.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Working principles of traditional and travelling-wave NMR.
Figure 2: Demonstration of travelling-wave NMR in an aqueous 10% ethanol solution.
Figure 3: Example of wave impedance matching in travelling-wave MRI.
Figure 4: In vivo results.
Figure 5: Travelling-wave MRI of very large samples.


  1. Bloch, F., Hansen, W. W. & Packard, M. The nuclear induction experiment. Phys. Rev. 70, 474–485 (1946)

    Article  ADS  CAS  Google Scholar 

  2. Purcell, E. M., Torrey, H. C. & Pound, R. V. Resonance absorption by nuclear magnetic moments in a solid. Phys. Rev. 69, 37–38 (1946)

    Article  ADS  CAS  Google Scholar 

  3. de Graaf, R. A. NMR Spectroscopy (Wiley, 2007)

    Book  Google Scholar 

  4. Lauterbur, P. C. Image Formation by Induced Local Interactions: Examples Employing Nuclear Magnetic Resonance. Nature 242, 190–197 (1973)

    Article  ADS  CAS  Google Scholar 

  5. Kumar, A., Welti, D. & Ernst, R. R. NMR Fourier zeugmatography. J. Magn. Reson. 18, 69–83 (1975)

    ADS  CAS  Google Scholar 

  6. Hahn, E. L. Nuclear induction due to free Larmor precession. Phys. Rev. 77, 297–298 (1950)

    Article  ADS  CAS  Google Scholar 

  7. Hayes, C. E., Edelstein, W. A., Schenck, J. F., Mueller, O. M. & Eash, M. An efficient, highly homogeneous radiofrequency coil for whole-body NMR imaging at 1.5 T. J. Magn. Reson. 63, 622–628 (1985)

    ADS  CAS  Google Scholar 

  8. Tropp, J. Theory of the birdcage resonator. J. Magn. Reson. 82, 51–62 (1989)

    ADS  Google Scholar 

  9. Roemer, P. B., Edelstein, W. A., Hayes, C. E., Souza, S. P. & Mueller, O. M. The NMR phased array. Magn. Reson. Med. 16, 192–225 (1990)

    Article  CAS  Google Scholar 

  10. Vaughan, J. T., Hetherington, H. P., Otu, J. O., Pan, J. W. & Pohost, G. M. High frequency volume coils for clinical NMR imaging and spectroscopy. Magn. Reson. Med. 32, 206–218 (1994)

    Article  CAS  Google Scholar 

  11. Wiltshire, M. C. K. et al. Microstructured magnetic materials for RF flux guides in magnetic resonance imaging. Science 291, 849–851 (2001)

    Article  ADS  CAS  Google Scholar 

  12. Day, E. P. Detection of NMR using a Josephson-junction magnetometer. Phys. Rev. Lett. 29, 540–542 (1972)

    Article  ADS  CAS  Google Scholar 

  13. Savukov, I. M. & Romalis, M. V. NMR detection with an atomic magnetometer. Phys. Rev. Lett. 94, 123001 (2005)

    Article  ADS  CAS  Google Scholar 

  14. Boero, G., Besse, P.-A. & Popovic, R. Hall detection of magnetic resonance. Appl. Phys. Lett. 79, 1498–1501 (2001)

    Article  ADS  CAS  Google Scholar 

  15. Verpillat, F. et al. Remote detection of nuclear magnetic resonance with an anisotropic magnetoresistive sensor. Proc. Natl Acad. Sci. USA 105, 2271–2273 (2008)

    Article  ADS  CAS  Google Scholar 

  16. Vaughan, T. et al. 9.4T human MRI: Preliminary results. Magn. Reson. Med. 56, 1274–1282 (2006)

    Article  Google Scholar 

  17. Atkinson, I. C., Renteria, L., Burd, H., Pliskin, N. H. & Thulborn, K. R. Safety of human MRI at static fields above the FDA 8T guideline: Sodium imaging at 9.4T does not affect vital signs or cognitive ability. J. Magn. Reson. Imaging 26, 1222–1227 (2007)

    Article  Google Scholar 

  18. Balanis, C. A. Antenna Theory: Analysis and Design 2nd edn, Ch. 14 (Wiley, 2005)

    Google Scholar 

  19. Bogdanov, G. & Ludwig, R. Coupled microstrip line transverse electromagnetic resonator model for high-field magnetic resonance imaging. Magn. Reson. Med. 47, 579–593 (2002)

    Article  CAS  Google Scholar 

  20. Harpen, M. D. Cylindrical coils near self-resonance. Magn. Reson. Med. 30, 489–493 (1993)

    Article  CAS  Google Scholar 

  21. Hoult, D. I. The principle of reciprocity in signal strength calculations: a mathematical guide. Concepts Magn. Reson. 12, 173–187 (2000)

    Article  CAS  Google Scholar 

  22. Gulla, A. F. & Budil, D. E. Engineering and design concepts for quasioptical high-field electron paramagnetic resonance. Concepts Magn. Reson. B 22B, 15–36 (2004)

    Article  Google Scholar 

  23. Boyd, R. W. Nonlinear Optics (Elsevier Science, 2003)

    Google Scholar 

  24. Kurnit, N. A., Abella, I. D. & Hartmann, S. R. Observation of a photon echo. Phys. Rev. Lett. 13, 567–568 (1964)

    Article  ADS  CAS  Google Scholar 

  25. Armstrong, J. A., Bloembergen, N., Ducuing, J. & Pershan, P. S. Light waves at the boundary of nonlinear media. Phys. Rev. 128, 606–622 (1962)

    Article  MathSciNet  Google Scholar 

  26. McCall, S. L. & Hahn, E. L. Self-induced transparency. Phys. Rev. 183, 457–490 (1969)

    Article  ADS  Google Scholar 

  27. Bock, N. A., Konyer, N. B. & Henkelman, R. M. Multiple-mouse MRI. Magn. Reson. Med. 49, 158–167 (2003)

    Article  Google Scholar 

  28. Christ, A. et al. Development of CAD based anatomical human body models of two adults and two children. EBEA 2007, abstr. S-4-2 (8th Internat. Congr. Eur. BioElectromag. Assoc., 2007)

    Google Scholar 

Download references


We thank N. van den Berg and A. Trabesinger for discussions. We are also grateful to P. Boesiger for his leading role in creating the 7T facility. This work was funded in part by the Swiss National Science Foundation (Project 116400) and by the Velux Foundation. Technical support from Philips Healthcare is also gratefully acknowledged.

Author Contributions D.O.B.: basic concept, antenna design and construction, bench experiments, magnetic resonance experiments, manuscript. N.D.Z.: conceptual considerations, assistance with antenna design, assistance with bench and magnetic resonance experiments, editing. J.F.: conceptual considerations, FDTD models, radio-frequency safety validation, editing. J.P.: FDTD models. K.P.P.: conceptual considerations, assistance with magnetic resonance experiments, manuscript, supervision.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Klaas P. Pruessmann.

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Brunner, D., De Zanche, N., Fröhlich, J. et al. Travelling-wave nuclear magnetic resonance. Nature 457, 994–998 (2009).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing