Skip to main content
Log in

On spatially selective RF excitation and its analogy with spiral MR image acquisition

  • Published:
Magnetic Resonance Materials in Physics, Biology and Medicine Aims and scope Submit manuscript

Abstract

The basic principles of the design of spatially selective RF pulses are described, and their analogy with MR image acquisition and reconstruction is shown. The paper focuses on RF-pulse design and imaging schemes in which spiral k-space trajectories are used. The sensitivity of RF excitation to gradient-system imperfections and to spatially varying off-resonance are analyzed, and suitable measures of correction are discussed. The spatial resolution obtainable with selective RF pulses and the consequences of the linearity of the pulse-design problem are examined. Phantom experiments showing the performance of multidimensional spatially selective RF pulses further illustrate the analogy with MR image acquisition.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Pauly JM, Nishimura DG, Macovski A. Ak-space analysis of small-tip-angle excitation. J Magn Reson 1989;81:43–56.

    Google Scholar 

  2. Hardy CJ, Cline HE. Spatial localization in two dimensions using NMR designer pulses. J Magn Reson 1989;82:647–54.

    Google Scholar 

  3. Pauly JM, Nishimura DG, Macovski A. A linear class of large-tip-angle selective excitation pulses. J Magn Reson 1989;82:571–87.

    Google Scholar 

  4. Hardy CJ, Cline HE. Broadband nuclear magnetic resonance pulses with two-dimensional spatial selectivity. J Appl Phys 1989;66(4):1513–6.

    Article  Google Scholar 

  5. Liu YL, Riederer SJ, Rossmann PJ, Grimm RC, Debbins JP, Ehman RL. A monitoring, feedback, and triggering system for reproducible breath-hold, MR imaging. Mag Reson Med 1993;30:507–11.

    Article  CAS  Google Scholar 

  6. Hardy CJ, Pearlman JD, Moore JR, Roemer PB, Cline HE. Rapid NMR cardiography with a half-echo M-mode method. J Comput Assist Tomogr 1991;15:868–74.

    Article  PubMed  CAS  Google Scholar 

  7. Hardy CJ, Darrow RD, Nieters EJ, et al. Real time acquisition, display, and interactive graphic control of NMR cardiac profiles and images. Mag Reson Med 1993;29:667–73.

    Article  CAS  Google Scholar 

  8. Hardy CJ, Bottomley P. A31P Spectroscopic localization using pinwheel NMR excitation pulses. Mag Reson Med 1991;17:315–27.

    Article  CAS  Google Scholar 

  9. Schäffter T, Börnert P and Leibfritz D. Comparison of 1D versus 2D pulses for outer volume suppression. In: Proc. SMR, 3rd Annual Meeting, Nice, 1995, p. 560.

  10. Heid O. Fourier spliced pencil Imaging. In: Proc. SMR, 3rd Annual Meeting, 1995, Nice, p. 488.

  11. Börnert P, Schäffter T. 2D RF Pulse encoded reduced FOV Imaging for scan time reduction. In: Proc. ISMRM, 5th Annual Meeting, Vancouver, 1997, p. 140.

  12. Börnert P, Schäffter T. Curved slice Imaging. Mag Reson Med 1996;36:932–9.

    Article  Google Scholar 

  13. Börnert P. 2D-RF pulse encoding for curved slice MRI. In Proc., SMR, 3rd Annual Meeting, 1995, Nice, p. 558.

  14. King KF, Foo TKF, Crawford CR. Optimized gradient wave-forms for spiral scanning. Mag Reson Med 1995;34:156–60.

    Article  CAS  Google Scholar 

  15. Mansfield P. Multi-planar image formation using NMR spin echoes. J Phys C 1997;10:L55–8.

    Article  Google Scholar 

  16. Sera I, Macura S. Excitation of arbitrary shapes by gradient optimized random walk in discretek-space. Mag Reson Med 1997;37:920–31.

    Article  Google Scholar 

  17. Ahn CB, Kim JH, Cho ZH. High-speed spiral-scan echo planar NMR imaging-1. IEEE Trans Med Imag 1986;5:2–7.

    Article  CAS  Google Scholar 

  18. Twieg DB. The k-space trajectory formulation of the NMR imaging process with applications in the analysis and synthesis of imaging methods. Med Phys 1983;10(5):610–21.

    Article  PubMed  CAS  Google Scholar 

  19. Ljunggren S. A simple graphical representation of Fourier-based imaging methods. J Magn Reson 1983;54:338–43.

    Google Scholar 

  20. Hould DI. The solution of the Bloch equations in the presence of a varyingB 1 field—an approach to selective pulse analysis. J Mag Reson 1979;35:69–86.

    Google Scholar 

  21. Hoge RD, Remi Kwan KS, Pike GB. Density compensation functions for Spiral MRI. Mag Reson Med 1997;38:117–28.

    Article  CAS  Google Scholar 

  22. Hardy CJ, Cline HE, Bottomley PA. Correcting for nonuniformk-space sampling in two-dimensional NMR selective excitation. J Magn Reson 1990;87:639–45.

    Google Scholar 

  23. Jackson JI, Meyer CH, Nishimura DG, Makovski A. Selection of a convolution function for Fourier inversion using gridding. IEEE Trans Med Imag 1985;10:473–8.

    Article  Google Scholar 

  24. Maeda A, Sano K, Yokoyama T. Reconstructions by weighted correlation for MRI with time-varying gradients. IEEE Trans Med Imag 1988;7:26–31.

    Article  CAS  Google Scholar 

  25. Rasche V, Proksa R. Reconstruction of MR images from data sampled along arbitraryk-space trajectories. In: Proc. ISMRM, 6th Annual Meeting, Sydney, 1998, p. 668.

  26. Takahashi A, Peters T. Compensation of multi-dimensional selective excitation pulses using measuredk-space trajectories. Mag Reson Med 1995;34:446–56.

    Article  CAS  Google Scholar 

  27. Mason GF, Harshbarger T, Herington H, Zhang Y, Prohost G, Twieg DB. A method to measure arbitraryk-space trajectories for rapid MR Imaging. Mag Reson Med 1997;38:492–6.

    Article  CAS  Google Scholar 

  28. Ding X, Tkach J, Ruggieri P, Perl J, Masaryk T. Improvement of Spiral MRI with the measured k-space trajectory. J Magn Reson Imag 1997;7:938–40.

    Article  CAS  Google Scholar 

  29. Pauly JM, Conolly S, Nishimura D, Macovski A. Slice-selective excitation for very shortT 2 species. In: Proc. SMRM, 8th Annual Meeting, Amsterdam. 1989, p. 28.

  30. Bracewell RN. The Fourier Transform and its Applications. New York: McGraw Hill, 1986.

    Google Scholar 

  31. Lauzon ML, Rutt BK. Effects of Polar Sampling ink-Space. Mag Reson Med 1996;36:940–9.

    Article  CAS  Google Scholar 

  32. Wright GA, Pauly J, Macovski A. DecreasingB 0 sensitivity of long RF pulses. In: Proc. SMRM, 12th Annual Meeting, New York, 1993, p. 423.

  33. Morell G, Macovski A. Three-dimensional spectral-spatial excitation. Mag Reson Med 1997;37:378–86.

    Article  Google Scholar 

  34. Man LC, Pauly JM, Macovski A. Multifrequency interpolation for fast off-resonance correction. Mag Reson Med 1997;37:785–92.

    Article  CAS  Google Scholar 

  35. Scheffler K, Henning J. Frequency resolved single-shot MR Imaging using stochastick-space trajectories. Mag Reson Med 1996;35:569–76.

    CAS  Google Scholar 

  36. Shomberg H, Börnert P. Off-resonance correction of nD spatially selective RF pulses. In: Proc. ISMRM, 6th Annual Meeting, Sydney, 1998, p. 2059.

  37. Noll DC, Meyer CH, Pauly JM, Nishimura GD, Macovski A. A homogeneity correction method for magnetic resonance imaging with time-varying gradients. IEEE Trans Med Imag 1992;10:629–37.

    Article  Google Scholar 

  38. Noll DC. Reconstruction techniques for magnetic resonance imaging. PhD Thesis, Stanford University, 1991.

  39. Vlaardingerbroek MT, den Boer JA. Magnetic Resonance Imaging: Theory and Practice. Berlin: Springer, 1997.

    Google Scholar 

  40. Aldefeld B, Börnert P. Effects of gradient anisotropy in MRI. Mag Reson Med 1998;39:606–14.

    Article  CAS  Google Scholar 

  41. Block W, Pauly J, Nishimura D. RARE spiralT 2-weighted Imaging. Mag Reson Med 1997;37:582–90.

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Börnert, P., Aldefeld, B. On spatially selective RF excitation and its analogy with spiral MR image acquisition. MAGMA 7, 166–178 (1998). https://doi.org/10.1007/BF02591334

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02591334

Keywords

Navigation