Adaptively regularized gradient coils for reduced local heating

Poole, M., Sanchez Lopez, H. and Crozier, S. (2008) Adaptively regularized gradient coils for reduced local heating. Concepts in Magnetic Resonance Part B: Magnetic Resonance Engineering, 33B 4: 220-227. doi:10.1002/cmr.b.20125

Author Poole, M.
Sanchez Lopez, H.
Crozier, S.
Title Adaptively regularized gradient coils for reduced local heating
Journal name Concepts in Magnetic Resonance Part B: Magnetic Resonance Engineering   Check publisher's open access policy
ISSN 1552-5031
Publication date 2008-10-01
Year available 2008
Sub-type Article (original research)
DOI 10.1002/cmr.b.20125
Open Access Status
Volume 33B
Issue 4
Start page 220
End page 227
Total pages 8
Editor Trificante, D.D.
Place of publication USA
Publisher John Wiley & Sons Inc.
Language eng
Subject C1
090399 Biomedical Engineering not elsewhere classified
970109 Expanding Knowledge in Engineering
Abstract Gradient and shim coil design is an inverse problem in which the objective is to generate a magnetic field with an error that falls within acceptable limits while optimizing some other property of the coil. This problem can be solved using a boundary element method via regularized matrix inversion. However, it is not possible to optimize properties that are not linear-least-squares with respect to the solutions using this method. In this work, we employ adaptive regularization to design coils with reduced maximum local current density, which is not a linear-least-squares problem. Reducing the maximum local current density allows the design of coils with lower maximum local Joule heating for the same gradient field strength and uniformity. Excessive local heating can be the cause of thermal drift and localized gradient failure. The minimum spacing between wires is increased by this method, permitting the design of more efficient coils for a given minimum wire spacing constraint as dictated by the method of manufacture. The adaptive regularization method, as formulated within the inverse boundary element method (IBEM) coil design framework, is described and results from three types of adaptively regularized coils are presented. The maximum local current densities of the coils are shown to be significantly reduced by adaptive regularization at the expense of some increase in their inductances and resistances. © 2008 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 33B: 220-227, 2008
Keyword Gradient Coils
Shim Coils
adaptive regularization
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2009 Higher Education Research Data Collection
School of Information Technology and Electrical Engineering Publications
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Citation counts: TR Web of Science Citation Count  Cited 17 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 18 times in Scopus Article | Citations
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Created: Wed, 15 Apr 2009, 23:09:39 EST by Ms Kimberley Nunes on behalf of School of Information Technol and Elec Engineering