A 32-channel parallel transmit system add-on for 7T MRI


Autoři: Stephan Orzada aff001;  Klaus Solbach aff002;  Marcel Gratz aff001;  Sascha Brunheim aff001;  Thomas M. Fiedler aff004;  Sören Johst aff001;  Andreas K. Bitz aff004;  Samaneh Shooshtary aff002;  Ashraf Abuelhaija aff002;  Maximilian N. Voelker aff001;  Stefan H. G. Rietsch aff001;  Oliver Kraff aff001;  Stefan Maderwald aff001;  Martina Flöser aff004;  Mark Oehmigen aff003;  Harald H. Quick aff001;  Mark E. Ladd aff001
Působiště autorů: Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany aff001;  RF & Microwave Technology, University of Duisburg-Essen, Duisburg, Germany aff002;  High-Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany aff003;  Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany aff004;  Electromagnetic Theory and Applied Mathematics, Faculty of Electrical Engineering and Information Technology, FH Aachen – University of Applied Sciences, Aachen, Germany aff005;  Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany aff006
Vyšlo v časopise: PLoS ONE 14(9)
Kategorie: Research Article
doi: https://doi.org/10.1371/journal.pone.0222452

Souhrn

Purpose

A 32-channel parallel transmit (pTx) add-on for 7 Tesla whole-body imaging is presented. First results are shown for phantom and in-vivo imaging.

Methods

The add-on system consists of a large number of hardware components, including modulators, amplifiers, SAR supervision, peripheral devices, a control computer, and an integrated 32-channel transmit/receive body array. B1+ maps in a phantom as well as B1+ maps and structural images in large volunteers are acquired to demonstrate the functionality of the system. EM simulations are used to ensure safe operation.

Results

Good agreement between simulation and experiment is shown. Phantom and in-vivo acquisitions show a field of view of up to 50 cm in z-direction. Selective excitation with 100 kHz sampling rate is possible. The add-on system does not affect the quality of the original single-channel system.

Conclusion

The presented 32-channel parallel transmit system shows promising performance for ultra-high field whole-body imaging.

Klíčová slova:

Medicine and health sciences – Diagnostic medicine – Diagnostic radiology – Magnetic resonance imaging – Radiology and imaging – Research and analysis methods – Imaging techniques – In vivo imaging – Engineering and technology – Signal processing – Signal amplification – Modulation – Electronics engineering – Logic circuits – Electronics – Capacitors – Physical sciences – Materials science – Materials – Magnets – Social sciences – Economics – Commerce – Vendors


Zdroje

1. Pohmann R, Speck O, Scheffler K. Signal-to-noise ratio and MR tissue parameters in human brain imaging at 3, 7, and 9.4 tesla using current receive coil arrays. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2016 Feb;75(2):801–9. 25820458.

2. Pfrommer A, Henning A. The ultimate intrinsic signal-to-noise ratio of loop- and dipole-like current patterns in a realistic human head model. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2018 Nov;80(5):2122–38. 29536567.

3. Hoult DI, Phil D. Sensitivity and power deposition in a high-field imaging experiment. Journal of magnetic resonance imaging: JMRI. 2000 Jul;12(1):46–67. 10931564.

4. Roschmann P. Radiofrequency penetration and absorption in the human body: limitations to high-field whole-body nuclear magnetic resonance imaging. Medical physics. 1987 Nov-Dec;14(6):922–31. 3696080.

5. Van de Moortele PF, Akgun C, Adriany G, Moeller S, Ritter J, Collins CM, et al. B(1) destructive interferences and spatial phase patterns at 7 T with a head transceiver array coil. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2005 Dec;54(6):1503–18. 16270333.

6. van Kalleveen IM, Koning W, Boer VO, Luijten PR, Zwanenburg JJ, Klomp DW. Adiabatic turbo spin echo in human applications at 7 T. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2012 Aug;68(2):580–7. 22213273.

7. Collins CM, Liu W, Swift BJ, Smith MB. Combination of optimized transmit arrays and some receive array reconstruction methods can yield homogeneous images at very high frequencies. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2005 Dec;54(6):1327–32. 16270331.

8. Metzger GJ, Snyder C, Akgun C, Vaughan T, Ugurbil K, Van de Moortele PF. Local B1+ shimming for prostate imaging with transceiver arrays at 7T based on subject-dependent transmit phase measurements. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2008 Feb;59(2):396–409. doi: 10.1002/mrm.21476 18228604.

9. Cloos MA, Boulant N, Luong M, Ferrand G, Giacomini E, Le Bihan D, et al. kT -points: short three-dimensional tailored RF pulses for flip-angle homogenization over an extended volume. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2012 Jan;67(1):72–80. 21590724.

10. Setsompop K, Alagappan V, Gagoski B, Witzel T, Polimeni J, Potthast A, et al. Slice-selective RF pulses for in vivo B1+ inhomogeneity mitigation at 7 tesla using parallel RF excitation with a 16-element coil. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2008 Dec;60(6):1422–32. doi: 10.1002/mrm.21739 19025908.

11. Saekho S, Yip CY, Noll DC, Boada FE, Stenger VA. Fast-kz three-dimensional tailored radiofrequency pulse for reduced B1 inhomogeneity. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2006 Apr;55(4):719–24. doi: 10.1002/mrm.20840 16526012.

12. Grissom W, Yip CY, Zhang Z, Stenger VA, Fessler JA, Noll DC. Spatial domain method for the design of RF pulses in multicoil parallel excitation. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2006 Sep;56(3):620–9. 16894579.

13. Katscher U, Bornert P, Leussler C, van den Brink JS. Transmit SENSE. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2003 Jan;49(1):144–50. 12509830.

14. Orzada S, Maderwald S, Poser BA, Bitz AK, Quick HH, Ladd ME. RF excitation using time interleaved acquisition of modes (TIAMO) to address B1 inhomogeneity in high-field MRI. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2010 Aug;64(2):327–33. 20574991.

15. Lattanzi R, Sodickson DK, Grant AK, Zhu Y. Electrodynamic constraints on homogeneity and radiofrequency power deposition in multiple coil excitations. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2009 Feb;61(2):315–34. doi: 10.1002/mrm.21782 19165885.

16. Umutlu L, Bitz AK, Maderwald S, Orzada S, Kinner S, Kraff O, et al. Contrast-enhanced ultra-high-field liver MRI: a feasibility trial. European journal of radiology. 2013 May;82(5):760–7. doi: 10.1016/j.ejrad.2011.07.004 21862273.

17. Wu X, Schmitter S, Auerbach EJ, Ugurbil K, Van de Moortele PF. Mitigating transmit B 1 inhomogeneity in the liver at 7T using multi-spoke parallel transmit RF pulse design. Quantitative imaging in medicine and surgery. 2014 Feb;4(1):4–10. doi: 10.3978/j.issn.2223-4292.2014.02.06 24649429.

18. Umutlu L, Maderwald S, Kinner S, Kraff O, Bitz AK, Orzada S, et al. First-pass contrast-enhanced renal MRA at 7 Tesla: initial results. European radiology. 2013 Apr;23(4):1059–66. doi: 10.1007/s00330-012-2666-0 23064714.

19. Luttje MP, Italiaander MG, Arteaga de Castro CS, van der Kemp WJ, Luijten PR, van Vulpen M, et al. (31) P MR spectroscopic imaging combined with (1) H MR spectroscopic imaging in the human prostate using a double tuned endorectal coil at 7T. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2014 Dec;72(6):1516–21. 24357271.

20. Vos EK, Lagemaat MW, Barentsz JO, Futterer JJ, Zamecnik P, Roozen H, et al. Image quality and cancer visibility of T2-weighted magnetic resonance imaging of the prostate at 7 Tesla. European radiology. 2014 Aug;24(8):1950–8. doi: 10.1007/s00330-014-3234-6 24865699.

21. Metzger GJ, van de Moortele PF, Akgun C, Snyder CJ, Moeller S, Strupp J, et al. Performance of external and internal coil configurations for prostate investigations at 7 T. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2010 Dec;64(6):1625–39. doi: 10.1002/mrm.22552 20740657.

22. Umutlu L, Kraff O, Fischer A, Kinner S, Maderwald S, Nassenstein K, et al. Seven-Tesla MRI of the female pelvis. European radiology. 2013 Sep;23(9):2364–73. doi: 10.1007/s00330-013-2868-0 23645332.

23. Chang G, Deniz CM, Honig S, Egol K, Regatte RR, Zhu Y, et al. MRI of the hip at 7T: feasibility of bone microarchitecture, high-resolution cartilage, and clinical imaging. Journal of magnetic resonance imaging: JMRI. 2014 Jun;39(6):1384–93. doi: 10.1002/jmri.24305 24115554.

24. Theysohn JM, Kraff O, Orzada S, Theysohn N, Classen T, Landgraeber S, et al. Bilateral hip imaging at 7 Tesla using a multi-channel transmit technology: initial results presenting anatomical detail in healthy volunteers and pathological changes in patients with avascular necrosis of the femoral head. Skeletal radiology. 2013 Nov;42(11):1555–63. doi: 10.1007/s00256-013-1698-0 23955579.

25. Brown R, Deniz CM, Zhang B, Chang G, Sodickson DK, Wiggins GC. Design and application of combined 8-channel transmit and 10-channel receive arrays and radiofrequency shimming for 7-T shoulder magnetic resonance imaging. Investigative radiology. 2014 Jan;49(1):35–47. doi: 10.1097/RLI.0b013e3182a5662d 24056112.

26. Rietsch SHG, Pfaffenrot V, Bitz AK, Orzada S, Brunheim S, Lazik-Palm A, et al. An 8-channel transceiver 7-channel receive RF coil setup for high SNR ultrahigh-field MRI of the shoulder at 7T. Medical physics. 2017 Dec;44(12):6195–208. doi: 10.1002/mp.12612 28976586.

27. von Knobelsdorff-Brenkenhoff F, Tkachenko V, Winter L, Rieger J, Thalhammer C, Hezel F, et al. Assessment of the right ventricle with cardiovascular magnetic resonance at 7 Tesla. Journal of cardiovascular magnetic resonance: official journal of the Society for Cardiovascular Magnetic Resonance. 2013;15:23. doi: 10.1186/1532-429X-15-23 23497030.

28. Vossen M, Teeuwisse W, Reijnierse M, Collins CM, Smith NB, Webb AG. A radiofrequency coil configuration for imaging the human vertebral column at 7 T. Journal of magnetic resonance. 2011 Feb;208(2):291–7. doi: 10.1016/j.jmr.2010.11.004 21134773.

29. Brown R, Storey P, Geppert C, McGorty K, Klautau Leite AP, Babb J, et al. Breast MRI at 7 Tesla with a bilateral coil and robust fat suppression. Journal of magnetic resonance imaging: JMRI. 2014 Mar;39(3):540–9. doi: 10.1002/jmri.24205 24123517.

30. van der Velden TA, Italiaander M, van der Kemp WJ, Raaijmakers AJ, Schmitz AM, Luijten PR, et al. Radiofrequency configuration to facilitate bilateral breast (31) P MR spectroscopic imaging and high-resolution MRI at 7 Tesla. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2015 Dec;74(6):1803–10. 25521345.

31. Fischer A, Maderwald S, Johst S, Orzada S, Ladd ME, Umutlu L, et al. Initial evaluation of non-contrast-enhanced magnetic resonance angiography in patients with peripheral arterial occlusive disease at 7 T. Investigative radiology. 2014 May;49(5):331–8. doi: 10.1097/RLI.0000000000000044 24637590.

32. Orzada S, Bitz AK, Johst S, Gratz M, Volker MN, Kraff O, et al. Analysis of an Integrated 8-Channel Tx/Rx Body Array for Use as a Body Coil in 7-Tesla MRI. Front Phys. 2017 Jun 7;5.

33. Paska J, Cloos MA, Wiggins GC. A rigid, stand-off hybrid dipole, and birdcage coil array for 7 T body imaging. Magnetic Resonance in Medicine. 2018 Aug;80(2):822–32. doi: 10.1002/mrm.27048 29250833

34. Vaughan JT, Snyder C, Delabarre L, Tian J, Adriany G, Andersen P, et al. Clinical Imaging at 7T with a 16 Channel Whole Body Coil and 32 Receive Channels. In: Proceedings of the 17th scientific meeting, International Society for Magnetic Resonance in Medicine, Honolulu, p 392. 2009.

35. Sooshtary S, Gratz M, Ladd ME, Solbach K. High-Speed RF Modulation System for 32 Parallel Transmission Channels at 7T. In: Proceedings of the 22nd scientific meeting, International Society for Magnetic Resonance in Medicine, Milan, p 544. 2014.

36. Solbach K, Abuelhaija A, Shooshtary S. Near-Magnet Power Amplifier with built-in Coil Current Sensing. Proc Intl Soc Mag Reson Med 22. 2014:1287.

37. Orzada S, Ladd ME, Bitz AK. A method to approximate maximum local SAR in multichannel transmit MR systems without transmit phase information. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2016 Sep 08. 27604749.

38. Orzada S, Bitz AK, Solbach K, Ladd ME. A receive chain add-on for implementation of a 32-channel integrated Tx/Rx body coil and use of local receive arrays at 7 Tesla. In: Proceedings of the 23rd scientific meeting, International Society for Magnetic Resonance in Medicine, Toronto, p 3134. 2015.

39. Orzada S, Bitz AK, Kraff O, Oehmigen M, Gratz M, Johst S, et al. A 32-Channel Integrated Body Coil for 7 Tesla Whole-Body Imaging. Proc Intl Soc Mag Reson Med 24. 2016:167.

40. Rietsch SHG, Quick HH, Orzada S. Impact of different meander sizes on the RF transmit performance and coupling of microstrip line elements at 7 T. Medical physics. 2015;42(8).

41. Watkins RD, Caverly RH, Doherty WE. 298MHz Micro miniature 2KW Transmit Receive Switch for 7.0 Tesla TR Arrays. Proc Intl Soc Mag Reson Med 20. 2012:2686.

42. Fiedler TM, Ladd ME, Bitz AK. SAR Simulations & Safety. NeuroImage. 2018 Mar;168:33–58. doi: 10.1016/j.neuroimage.2017.03.035 28336426.

43. Brunheim S, Gratz M, Johst S, Bitz AK, Fiedler TM, Ladd ME, et al. Fast and accurate multi-channel B1+ mapping based on the TIAMO technique for 7T UHF body MRI. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2018 May;79(5):2652–64. 28994132.

44. Christ A, Kainz W, Hahn EG, Honegger K, Zefferer M, Neufeld E, et al. The Virtual Family—development of surface-based anatomical models of two adults and two children for dosimetric simulations. Physics in medicine and biology. 2010 Jan 21;55(2):N23–38. doi: 10.1088/0031-9155/55/2/N01 20019402.

45. Eichfelder G, Gebhardt M. Local specific absorption rate control for parallel transmission by virtual observation points. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2011 Nov;66(5):1468–76. 21604294.

46. Völker MN, Kraff O, Pracht E, Wollrab A, Bitz AK, Stöcker T, et al. Quality Assurance Phantoms and Procedures for UHF MRI—The German Ultrahigh Field Imaging (GUFI) Approach. In: Proceedings of the 25th scientific meeting, International Society for Magnetic Resonance in Medicine, Honolulu, p 3912. 2017.

47. Friedman L, Glover GH. Report on a multicenter fMRI quality assurance protocol. Journal of magnetic resonance imaging: JMRI. 2006 Jun;23(6):827–39. 16649196.

48. Stang PP, Conolly SM, Santos JM, Pauly JM, Scott GC. Medusa: a scalable MR console using USB. IEEE transactions on medical imaging. 2012 Feb;31(2):370–9. doi: 10.1109/TMI.2011.2169681 21954200.

49. Han H, Moritz R, Oberacker E, Waiczies H, Niendorf T, Winter L. Open Source 3D Multipurpose Measurement System with Submillimetre Fidelity and First Application in Magnetic Resonance. Scientific reports. 2017 Oct 18;7(1):13452. doi: 10.1038/s41598-017-13824-z 29044156.

50. Rietsch SHG, Orzada S, Maderwald S, Brunheim S, Philips BWJ, Scheenen TWJ, et al. 7T ultra-high field body MR imaging with an 8-channel transmit/32-channel receive radiofrequency coil array. Medical physics. 2018 Jul;45(7):2978–90. doi: 10.1002/mp.12931 29679498.

51. Erturk MA, Raaijmakers AJ, Adriany G, Ugurbil K, Metzger GJ. A 16-channel combined loop-dipole transceiver array for 7 Tesla body MRI. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2017 Feb;77(2):884–94. doi: 10.1002/mrm.26153 26887533.

52. Raaijmakers AJ, Italiaander M, Voogt IJ, Luijten PR, Hoogduin JM, Klomp DW, et al. The fractionated dipole antenna: A new antenna for body imaging at 7 Tesla. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2016 Mar;75(3):1366–74. 25939890.

53. Rietsch SHG, Orzada S, Bitz AK, Gratz M, Ladd ME, Quick HH. Parallel transmit capability of various RF transmit elements and arrays at 7T MRI. Magnetic resonance in medicine: official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. 2018 Feb;79(2):1116–26. 28394080.

54. Rietsch SH, Orzada S, Weine J, Ruschen L, Handtke S, Berghs RM, et al. A 16-channel Rx-only radiofrequency coil for MR spine imaging at 7T. Proc Intl Soc Mag Reson Med 26. 2018:144.

55. Brunheim S, Orzada S, Johst S, Gratz M, Kohl J, Ladd ME, et al. 16-channel pTx body MRI for reduced field of view lumbar spine and kidney imaging at 7 Tesla. Proc Intl Soc Mag Reson Med 26. 2018:3393.


Článek vyšel v časopise

PLOS One


2019 Číslo 9
Nejčtenější tento týden