Journal article
Improving brain B0 shimming using an easy and accessible multi-coil shim array at ultra-high field
University of Copenhagen1
Philips Healthcare2
Massachusetts Institute of Technology3
Harvard University4
MRI Acquisition, Magnetic Resonance, Department of Health Technology, Technical University of Denmark5
Magnetic Resonance, Department of Health Technology, Technical University of Denmark6
Department of Health Technology, Technical University of Denmark7
Object : Improve shimming capabilities of ultra-high field systems, with addition of an accessible low-complexity B0 shim array for head MRI at 7 T. Materials and methods : An eight channel B0 shim coil array was designed as a tradeoff between shimming improvement and construction complexity, to provide an easy to use shim array that can be employed with the standard 7 T head coil.
The array was interfaced using an open-source eight-channel shim amplifier rack. Improvements in field homogeneity for whole-brain and slice-based shimming were compared to standard second-order shimming, and to more complex higher order dynamic shimming and shim arrays with 32 and 48 channels. Results : The eight-channel shim array provided 12% improvement in whole brain static shimming and provided 33% improvement when using slice-based shimming.
With this, the eight-channel array performed similar to third-order dynamic shimming (without the need for higher order eddy current compensation). More complex shim arrays with 32 and 48 channels performed better, but require a dedicated RF coil. Discussion : The designed eight-channel shim array provides a low-complexity and low-cost approach for improving B0 field shimming on an ultra-high field system.
In both static and dynamic shimming, it provides improved B0 homogeneity over standard shimming.
Language: | English |
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Publisher: | Springer International Publishing |
Year: | 2022 |
Pages: | 943-951 |
Journal subtitle: | Official Journal of the European Society for Magnetic Resonance in Medicine and Biology |
ISSN: | 13528661 and 09685243 |
Types: | Journal article |
DOI: | 10.1007/s10334-022-01014-6 |
ORCIDs: | 0000-0001-6026-3134 and Petersen, Esben Thade |