Skip to main content

Radiofrequency Coils

  • Chapter
  • First Online:
High-Field MR Imaging

Part of the book series: Medical Radiology ((Med Radiol Diagn Imaging))

  • 1280 Accesses

Abstract

Producing a homogenous radiofrequency field within the patient at high field is challenging since the electromagnetic wavelength inside the body is significantly less than the body dimensions. An associated problem is the spatially inhomogeneous electric field that can produce localized thermal hot-spots. The use of transmit array coils, in which the magnitude and phase of the inputs to each element of the array are individually controlled, can significantly improve the RF field uniformity within a patient. Despite the challenges, there are also exciting new designs for RF coils and possibilities to control the RF fields which can only be put into practice at high fields. This chapter explains the basic principles of radiofrequency transmission and reception with specific focus on the challenges of UHF-MR and gives an overview of the state-of-the-art in this rapidly changing field.

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

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 89.00
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 119.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 169.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

References

  • Adriany G, van de Moortele PF, Wiesinger F, Moeller S, Strupp JP, Andersen P, Snyder C, Zhang X, Chen W, Pruessmann KP, Boesiger P, Vaughan T, Ugurbil K (2005) Transmit and receive transmission line arrays for 7 Tesla parallel imaging. Magn Reson Med 53:434–445

    Article  PubMed  Google Scholar 

  • Adriany G, van de Moortele PF, Ritter J, Moeller S, Auerbach EJ, Akgun C, Snyder CJ, Vaughan T, Ugurbil K (2008) A geometrically adjustable 16-channel transmit/receive transmission line array for improved RF efficiency and parallel imaging performance at 7 Tesla. Magn Reson Med 59:590–597

    Article  PubMed  Google Scholar 

  • Behnia B, Webb AG (2004) MRI-monitored electromagnetic heating using iterative feedback control and phase interference mapping. Concepts Magn Reson B 23B:1–15

    Article  Google Scholar 

  • Behnia B, Suthar M, Webb AG (2002) Closed-loop feedback control of phased-array microwave heating using thermal measurements from magnetic resonance imaging. Concepts Magn Reson B 15:101–110

    Article  Google Scholar 

  • Blaimer M, Breuer F, Mueller M, Heidemann RM, Griswold MA, Jakob PM (2004) SMASH, SENSE, PILS, GRAPPA: how to choose the optimal method. Top Magn Reson Imaging 15:223–236

    Article  PubMed  Google Scholar 

  • Brunner DO, De Zanche N, Paska J, Froehlich J, Pruessmann KP (2008) Traveling wave MR on a whole-body system. International Society for Magnetic Resonance in Medicine, Toronto

    Google Scholar 

  • Collins CM, Smith MB (2001) Calculations of B1 distribution, SNR, and SAR for a surface coil adjacent to an anatomically-accurate human body model. Magn Reson Med 45:692–699

    Article  PubMed  CAS  Google Scholar 

  • Collins CM, Yang B, Yang QX, Smith MB (2002a) Numerical calculations of the static magnetic field in three-dimensional multi-tissue models of the human head. Magn Reson Imaging 20:413–424

    Article  PubMed  Google Scholar 

  • Collins CM, Yang QX, Wang JH, Zhang X, Liu H, Michaeli S, Zhu XH, Adriany G, Vaughan JT, Anderson P, Merkle H, Ugurbil K, Smith MB, Chen W (2002b) Different excitation and reception distributions with a single-loop transmit-receive surface coil near a head-sized spherical phantom at 300 MHz. Magn Reson Med 47:1026–1028

    Article  PubMed  CAS  Google Scholar 

  • Collins CM, Liu W, Wang J, Gruetter R, Vaughan JT, Ugurbil K, Smith MB (2004) Temperature and SAR calculations for a human head within volume and surface coils at 64 and 300 MHz. J Magn Reson Imaging 19:650–656

    Article  PubMed  Google Scholar 

  • Duyn JH, van GP, Li TQ, de Zwart JA, Koretsky AP, Fukunaga M (2007) High-field MRI of brain cortical substructure based on signal phase. Proc Natl Acad Sci USA 104:11796–11801

    Article  PubMed  CAS  Google Scholar 

  • Glover GH, Hayes CE, Pelc NJ, Edelstein WA, Mueller OM, Hart HR, Hardy CJ, Odonnell M, Barber WD (1985) Comparison of linear and circular-polarization for magnetic-resonance imaging. J Magn Reson 64:255–270

    CAS  Google Scholar 

  • Griswold MA, Jakob PM, Heidemann RM, Nittka M, Jellus V, Wang J, Kiefer B, Haase A (2002) Generalized autocalibrating partially parallel acquisitions (GRAPPA). Magn Reson Med 47:1202–1210

    Article  PubMed  Google Scholar 

  • Haines K, Smith NB, Webb AG (2010) New high dielectric constant materials for tailoring the B1 + distribution at high magnetic fields. J Magn Reson (in press)

    Google Scholar 

  • Hayes CE, Edelstein WA, Schenck JF, Mueller OM, Eash M (1985) An efficient, highly homogeneous radiofrequency coil for whole-body NMR imaging at 1.5-T. J Magn Reson 63:622–628

    CAS  Google Scholar 

  • Heidemann RM, Ozsarlak O, Parizel PM, Michiels J, Kiefer B, Jellus V, Muller M, Breuer F, Blaimer M, Griswold MA, Jakob PM (2003) A brief review of parallel magnetic resonance imaging. Eur Radiol 13:2323–2337

    Article  PubMed  Google Scholar 

  • Hoult DI (2009) The origins and present status of the radio wave controversy in NMR. Concepts Magn Reson A 34:193–216

    Google Scholar 

  • IEC (2002) International standard, medical equipment—part 2: particular requirements for the safetyof magnetic resonance equipment for medical diagnosis, 2nd revision. International electrotechnical commission 601-2-33

    Google Scholar 

  • Kang CK, Park CW, Han JY, Kim SH, Park CA, Kim KN, Hong SM, Kim YB, Lee KH, Cho ZH (2009) Imaging and analysis of lenticulostriate arteries using 7.0-Tesla magnetic resonance angiography. Magn Reson Med 61:136–144

    Article  PubMed  Google Scholar 

  • Katscher U, Bornert P, Leussler C, van den Brink JS (2003) Transmit SENSE. Magn Reson Med 49:144–150

    Article  PubMed  Google Scholar 

  • Katscher U, Bornert P, van den Brink JS (2004) Theoretical and numerical aspects of transmit SENSE. IEEE Trans Med Imaging 23:520–525

    Article  PubMed  Google Scholar 

  • Kowalski ME, Behnia B, Webb AG, Jin HM (2002) Optimization of electromagnetic phased-arrays for hyperthermia via magnetic resonance temperature estimation. IEEE Trans Microw Theory Tech 49:1229–1241

    Google Scholar 

  • Kurpad KN, Wright SM, Boskamp EB (2006) RF current element design for independent control of current amplitude and phase in transmit phased arrays. Concepts Magn Reson B 29B:75–83

    Article  Google Scholar 

  • Lee RF, Westgate CR, Weiss RG, Newman DC, Bottomley PA (2001) Planar strip array (PSA) for MRI. Magn Reson Med 45:673–683

    Article  PubMed  CAS  Google Scholar 

  • Lee RF, Hardy CJ, Sodickson DK, Bottomley PA (2004) Lumped-element planar strip array (LPSA) for parallel MRI. Magn Reson Med 51:172–183

    Article  PubMed  Google Scholar 

  • Lee W, Boskamp E, Grist T, Kurpad K (2009) Radiofrequency current source (RFCS) drive and decoupling technique for parallel transmit arrays using a high-power metal oxide semiconductor field-effect transistor (MOSFET). Magn Reson Med 62:218–228

    Article  PubMed  Google Scholar 

  • Li TQ, van GP, Merkle H, Talagala L, Koretsky AP, Duyn J (2006) Extensive heterogeneity in white matter intensity in high-resolution T2*-weighted MRI of the human brain at 7.0 T. Neuroimage 32:1032–1040

    Article  PubMed  Google Scholar 

  • Maderwald S, Ladd SC, Gizewski ER, Kraff O, Theysohn JM, Wicklow K, Moenninghoff C, Wanke I, Ladd ME, Quick HH (2008) To TOF or not to TOF: strategies for non-contrast-enhanced intracranial MRA at 7 T. MAGMA 21:159–167

    Article  PubMed  Google Scholar 

  • Metzger GJ, Snyder C, Akgun C, Vaughan T, Ugurbil K, van de Moortele PF (2008) Local B1 + shimming for prostate imaging with transceiver arrays at 7T based on subject-dependent transmit phase measurements. Magn Reson Med 59:396–409

    Article  PubMed  Google Scholar 

  • Monninghoff C, Maderwald S, Theysohn JM, Kraff O, Ladd SC, Ladd ME, Forsting M, Quick HH, Wanke I (2009) Evaluation of intracranial aneurysms with 7 T versus 1.5 T time-of-flight MR angiography—initial experience. Rofo 181:16–23

    PubMed  CAS  Google Scholar 

  • Pennes HH (1948) Analysis of skin, muscle and brachial arterial blood temperatures in the resting normal human forearm. Am J Physiol 155:459

    Google Scholar 

  • Pruessmann KP, Weiger M, Scheidegger MB, Boesiger P (1999) SENSE: sensitivity encoding for fast MRI. Magn Reson Med 42:952–962

    Article  PubMed  CAS  Google Scholar 

  • Roemer PB, Edelstein WA, Hayes CE, Souza SP, Mueller OM (1990) The NMR phased array. Magn Reson Med 16:192–225

    Article  PubMed  CAS  Google Scholar 

  • Schmitt M, Potthast A, Sosnovik DE, Polimeni JR, Wiggins GC, Triantafyllou C, Wald LL (2008) A 128-channel receive-only cardiac coil for highly accelerated cardiac MRI at 3 Tesla. Magn Reson Med 59:1431–1439

    Article  PubMed  Google Scholar 

  • Snyder CJ, DelaBarre L, Metzger GJ, van de Moortele PF, Akgun C, Ugurbil K, Vaughan JT (2009) Initial results of cardiac imaging at 7 Tesla. Magn Reson Med 61:517–524

    Article  PubMed  CAS  Google Scholar 

  • Sodickson DK, Manning WJ (1997) Simultaneous acquisition of spatial harmonics (SMASH): fast imaging with radiofrequency coil arrays. Magn Reson Med 38:591–603

    Article  PubMed  CAS  Google Scholar 

  • Sodickson DK, McKenzie CA (2001) A generalized approach to parallel magnetic resonance imaging. Med Phys 28:1629–1643

    Article  PubMed  CAS  Google Scholar 

  • Sullivan D (1991) Mathematical-methods for treatment planning in deep regional hyperthermia. IEEE Trans Microw Theory Tech 39:864–872

    Article  Google Scholar 

  • Tkac I, Oz G, Adriany G, Ugurbil K, Gruetter R (2009) In vivo 1H NMR spectroscopy of the human brain at high magnetic fields: metabolite quantification at 4T vs. 7T. Magn Reson Med 62:868–879

    Article  PubMed  CAS  Google Scholar 

  • Traficante DD (1989) Impedance: what it is and why it must be matched. Concepts Magn Reson 1:73–92

    Google Scholar 

  • van de Moortele PF, Akgun C, Adriany G, Moeller S, Ritter J, Collins CM, Smith MB, Vaughan JT, Ugurbil K (2005) B1 destructive interferences and spatial phase patterns at 7 T with a head transceiver array coil. Magn Reson Med 54:1503–1518

    Article  PubMed  Google Scholar 

  • van Elderen SG, Versluis MJ, Webb AG, Westenberg JJ, Doornbos J, Smith NB, de RA, Stuber M (2009) Initial results on in vivo human coronary MR angiography at 7 T. Magn Reson Med 62:1379–1384

    Article  PubMed  Google Scholar 

  • Vaughan JT, Hetherington HP, Otu JO, Pan JW, Pohost GM (1994) High frequency volume coils for clinical NMR imaging and spectroscopy. Magn Reson Med 32:206–218

    Article  PubMed  CAS  Google Scholar 

  • Vaughan JT, Adriany G, Snyder CJ, Tian J, Thiel T, Bolinger L, Liu H, DelaBarre L, Ugurbil K (2004) Efficient high-frequency body coil for high-field MRI. Magn Reson Med 52:851–859

    Article  PubMed  CAS  Google Scholar 

  • Vaughan T, DelaBarre L, Snyder C, Tian J, Akgun C, Shrivastava D, Liu W, Olson C, Adriany G, Strupp J, Andersen P, Gopinath A, van de Moortele PF, Garwood M, Ugurbil K (2006) 9.4T human MRI: preliminary results. Magn Reson Med 56:1274–1282

    Article  PubMed  Google Scholar 

  • Vaughan JT, Snyder CJ, DelaBarre LJ, Bolan PJ, Tian J, Bolinger L, Adriany G, Andersen P, Strupp J, Ugurbil K (2009) Whole-body imaging at 7T: preliminary results. Magn Reson Med 61:244–248

    Article  PubMed  Google Scholar 

  • Versluis MJ, Tsekos N, Smith NB, Webb AG (2009) Simple RF design for human functional and morphological cardiac imaging at 7tesla. J Magn Reson 200:161–166

    Article  PubMed  CAS  Google Scholar 

  • Wang J, Yang QX, Zhang X, Collins CM, Smith MB, Zhu XH, Adriany G, Ugurbil K, Chen W (2002) Polarization of the RF field in a human head at high field: a study with a quadrature surface coil at 7.0 T. Magn Reson Med 48:362–369

    Article  PubMed  Google Scholar 

  • Wang Z, Lin JC, Mao W, Liu W, Smith MB, Collins CM (2007) SAR and temperature: simulations and comparison to regulatory limits for MRI. J Magn Reson Imaging 26:437–441

    Article  PubMed  Google Scholar 

  • Webb AG, Collins CM, Kan HE, Versluis M, Smith NB (2010) Magn Reson Med 63:297–302

    Google Scholar 

  • Weihrauch M, Wust P, Weiser M, Nadobny J, Eisenhardt S, Budach V, Gellermann J (2007) Adaptation of antenna profiles for control of MR guided hyperthermia (HT) in a hybrid MR-HT system. Med Phys 34:4717–4725

    Article  PubMed  Google Scholar 

  • Wright SM, Magin RL, Kelton JR (1991) Arrays of mutually coupled receiver coils: theory and application. Magn Reson Med 17:252–268

    Article  PubMed  CAS  Google Scholar 

  • Wust P, Nadobny J, Felix R, Deuflhard P, Louis A, John W (1991) Strategies for optimized application of annular-phased-array systems in clinical hyperthermia. Int J Hyperthermia 7:157–173

    Article  PubMed  CAS  Google Scholar 

  • Yacoub E, Shmuel A, Pfeuffer J, van de Moortele PF, Adriany G, Andersen P, Vaughan JT, Merkle H, Ugurbil K, Hu X (2001) Imaging brain function in humans at 7 Tesla. Magn Reson Med 45:588–594

    Article  PubMed  CAS  Google Scholar 

  • Yang QX, Mao W, Wang J, Smith MB, Lei H, Zhang X, Ugurbil K, Chen W (2006) Manipulation of image intensity distribution at 7.0 T: passive RF shimming and focusing with dielectric materials. J Magn Reson Imaging 24:197–202

    Article  PubMed  CAS  Google Scholar 

  • Zhang XZ, Webb A (2004) Design of a capacitively decoupled transmit/receive NMR phased array for high field microscopy at 14.1 T. J Magn Reson 170:149–155

    Article  PubMed  CAS  Google Scholar 

  • Zwanenburg JJ, Hendrikse J, Takahara T, Visser F, Luijten PR (2008) MR angiography of the cerebral perforating arteries with magnetization prepared anatomical reference at 7 T: comparison with time-of-flight. J Magn Reson Imaging 28:1519–1526

    Article  PubMed  Google Scholar 

Download references

Acknowledgments

The MATLAB code used to generate values of dielectric constant versus frequency (http://pennstatehershey.org/web/nmrlab/resources/software/rftools) were provided by Chris Collins and Sukhoon Oh from the Penn State Center for NMR Research. Coil photographs were generously provided by Mark Ladd from the Erwin L. Hahn Institute, University of Essen-Duisberg and Chris Collins. Figures were also provided by Figures were kindly provided by Thomas Vaughan, Pierre-Francois van der Moortele, and Gregor Adriany from the Center for Magnetic Resonance Research, University of Minnesota.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Andrew G. Webb .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2012 Springer-Verlag Berlin Heidelberg

About this chapter

Cite this chapter

Webb, A.G. (2012). Radiofrequency Coils. In: Hennig, J., Speck, O. (eds) High-Field MR Imaging. Medical Radiology(). Springer, Berlin, Heidelberg. https://doi.org/10.1007/174_2010_131

Download citation

  • DOI: https://doi.org/10.1007/174_2010_131

  • Published:

  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-540-85087-8

  • Online ISBN: 978-3-540-85090-8

  • eBook Packages: MedicineMedicine (R0)

Publish with us

Policies and ethics