Random RF shimming may conceal possible local SAR hotspots for asymmetric parallel transmit coils

Kopanoglu, Emre ORCID: https://orcid.org/0000-0001-8982-4441, Tachrount, Mohamed, Meliado, Ettore Flavio, Klomp, Dennis, Evans, John and Wise, Richard G. ORCID: https://orcid.org/0000-0003-1700-2144 2019. Random RF shimming may conceal possible local SAR hotspots for asymmetric parallel transmit coils. Presented at: ISMRM 27th Annual Meeting & Exhibition, Montréal, QC, Canada, 11-16 May 2019. Proceedings of the ISMRM 27th Annual Meeting and Exhibition. Proceedings of the ISMRM. ISMRM, p. 4158.

Preview

PDF - Accepted Post-Print Version Download (554kB) | Preview

Abstract

While general-purpose pTx coils mostly have identical elements arranged symmetrically, coils built for a specific application may be asymmetrical. This asymmetry may lead to a high variation in local SAR distributions of individual coil-elements. For an arterial spin labelling pTx coil, we show that using 2,000,000 unconstrained random excitations to characterize the maximum local-SAR underestimates the local-SAR by 7%. We also show that for the investigated ASL coil, the neck elements, which could be exclusively used for labelling, yield 33% less SAR than the head-imaging coils. Therefore, 50% higher power limits can be used for labelling part of an ASL sequence than the imaging part.

Item Type:	Conference or Workshop Item - published (Poster)
Date Type:	Publication
Status:	Published
Schools:	Schools > Psychology Research Institutes & Centres > Cardiff University Brain Research Imaging Centre (CUBRIC)
Publisher:	ISMRM
ISSN:	1545-4428
Date of First Compliant Deposit:	24 February 2021
Date of Acceptance:	16 June 2019
Last Modified:	13 May 2026 14:15
URI:	https://orca.cardiff.ac.uk/id/eprint/140068

Actions (repository staff only)

Edit Item