Cape Town - 2026 ISMRM-ISMRT Annual Meeting and Exhibition
9 May 2026 – 14 May 2026 · Cape Town, South Africa
467-05-016 ISMRM Abstract

RF Shim Alternatives to Circular Polarization for Improving B_{1}^{+} Field Symmetry at 7T

Primary: Physics & Engineering - RF Arrays & Systems
Secondary: Physics & Engineering - RF Pulse Design & Fields
467-05-016 · Frontiers of System Design · Tuesday, 12 May, 4:00 PM–4:55 PM · Digital Posters Row H
Keywords: Optimization RF shimming B1 inhomogeneity Parallel Transmission (pTx) 7T MRI
Accepted
Sydney N Williams 1, Paul McElhinney2, Max Joris Hubmann3, Belinda Ding4, Cindy Lübeck5, Astrid Wollrab5, Shajan Gunamony2,6
1Medical Image Analysis and Biometry Lab, Universidad Rey Juan Carlos, Móstoles, Spain
2MR CoilTech Limited, Glasgow, United Kingdom
3Faculty of Electrical Engineering and Information Technology, Otto-von-Guericke University, Magdeburg, Germany
4NHS University Hospital Birmingham, Birmingham, United Kingdom
5Dept. Biomedical Magnetic Resonance, Otto-von-Guericke University, Magdeburg, Germany
6Imaging Center of Excellence, Glasgow, United Kingdom
Presenting Author: Sydney N Williams

Synopsis

Motivation:
Goals:
Approach:
Results:
Full abstract & presentation

The full text, figures, and any recorded presentation for this abstract are not shown here. Log in if you are a member or registered attendee with access.

Full abstracts, figures, and presentations for Cape Town - 2026 ISMRM-ISMRT Annual Meeting and Exhibition are available to registered attendees. This content becomes freely available to the public roughly two years after the meeting.

To request or purchase access, contact the ISMRM Central Office at info@ismrm.org.

Log in

References

1. Hoult, DI, “Sensitivity and Power Deposition in a High-Field Imaging Experiment,” J. Magn. Reson. Imaging, 2000; 12: 46-67. https://doi.org/10.1002/1522-2586(200007)12:1<46::AID-JMRI6>3.0.CO;2-D [doi]
2. Ibrahim, TS, Lee, R, Baertlein, BA, Kangarlu, A, Robitaille PL. “Application of finite difference time domain method for the design of birdcage RF head coils using multi-port excitations,” Magn Reson Imaging, 2000; 8(6):733-42. https://doi.org/10.1016/s0730-725x(00)00143-0 [doi]
3. Gras, V, Vignaud, A, Amadon, A, Le Bihan, D, and Boulant, N, “Universal pulses: A new concept for calibration-free parallel transmission,” Magn. Reson. Med., 2017; 77: 635-643. https://doi.org/10.1002/mrm.26148 [doi]
4. Massire, A, Mauconduit F, Gras, V, et al., “PASTEUR: Package of Anatomical Sequences Using Parallel Transmission Universal Pulses Now Available for MAGNETOM Terra,” Magnetom FLASH, 2022; 80(1):2-13. https://www.magnetomworld.siemens-healthineers.com/clinical-corner/case-studies/pasteur
5. Herrler J, Liebig P, Gumbrecht R, et al. “Fast online-customized (FOCUS) parallel transmission pulses: A combination of universal pulses and individual optimization.,” Magn. Reson. Med., 2021; 85: 3140–3153. https://doi.org/10.1002/mrm.28643 [doi]
6. Tomi-Tricot R, Sedlacik J, Endres J,et al., “Fully integrated scanner implementation of direct signal control for 2D T2-weighted TSE at ultra-high field”, Proc. Int. Soc. Magn. Reson. Med., 2021; Virtual, pp 0621.
7. Lowen D, Pracht ED, Gras V, et al., “Design of calibration-free RF pulses for T-weighted single-slab 3D turbo-spin-echo sequences at 7T utilizing parallel transmission,” Magn. Reson. Med., 2024; 92: 2037-2050. doi: 10.1002/mrm.30212 [doi]
8. Ding B, Williams SN, Dragonu I, et al. “Slice-specific B1+ shimming improves the repeatability of multishot DWI at 7 T,” Magn Reson Med., 2024; 92: 2560-2570. doi: 10.1002/mrm.30208 [doi]
9. Feinberg, DA, Beckett, AJS, Vu, AT, et al., “Next-generation MRI scanner designed for ultra-high-resolution human brain imaging at 7 Tesla,” Nat Methods, 2023; 20:2048–2057. https://doi.org/10.1038/s41592-023-02068-7 [doi]
10. Christ, A, Kainz, W, Hahn, EG, et al., “The Virtual Family—development of surface-based anatomical models of two adults and two children for dosimetric simulations,” Phys. Med. Biol., 2010; 55(2). https://iopscience.iop.org/article/10.1088/0031-9155/55/2/N01
11. Padormo, F, Beqiri, A, Hajnal, JV, and Malik, SJ, “Parallel transmission for ultrahigh-field imaging,” NMR Biomed., 2016; 29(9):1145-61. https://doi.org/10.1002/nbm.3313 [doi]
12. Fautz, H-P, Vogel, M, Gross, P , Kerr, A, Zhu, Y, “B1 mapping of coil arrays for parallel transmission”, Proc. Int. Soc. Magn. Reson. Med., 2009; Toronto, Canada, 1247.
13. Eichfelder, G and Gebhardt, M, “Local specific absorption rate control for parallel transmission by virtual observation points,” Magn. Reson. Med., 2011; 66(5):1468-76. https://doi.org/10.1002/mrm.22927 [doi]
14. Brouwer, EJP, van der Zwaag, W, Heij and J, Priovoulos N. “Easy-to-use B1+ shims for human brain imaging at 7 T,” Magn. Reson. Med., 2011; 94(5):2010-2022. https://doi.org/10.1002/mrm.30617 [doi]
15. Tomi-Tricot, R, Gras, V, Thirion B, et al., “SmartPulse, a machine learning approach for calibration-free dynamic RF shimming: Preliminary study in a clinical environment,” Magn. Reson. Med., 2019; 82(6):2016-2031. https://doi.org/10.1002/mrm.27870 [doi]

Cite this abstract

http://echo.ismrm.org/p/ISMRM2026/467-05-016