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Heating caused by gradient coils is a considerable concern in the operation of MRI scanners. Hot spots can occur in regions where the gradient coil windings are closely spaced. These problem areas are particularly common in the design of gradient coils with asymmetrically located target regions. In this paper, an extension of an existing coil design method is described, to enable the design of asymmetric gradient coils with reduced hot spot temperatures. An improved model is presented for predicting steady-state spatial temperature distributions for gradient coils. A great amount of flexibility is afforded by this model to consider a wide range of geometries and system material properties. A feature of the temperature distribution related to the temperature gradient is used in a relaxed fixed point iteration routine for successively altering coil windings to have a lower hot spot temperature. Results show that significant reductions in peak temperature are possible at little or no cost to coil performance when compared to minimum power coils of equivalent field error.

Item Type:	Refereed Article
Keywords:	Cooling , MRI , gradient coil design , heating , hot spot , inverse method , nonlinear optimization , temperature , thermal
Research Division:	Mathematical Sciences
Research Group:	Numerical and computational mathematics
Research Field:	Optimisation
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in engineering
UTAS Author:	While, PT (Dr Peter While)
UTAS Author:	Forbes, LK (Professor Larry Forbes)
ID Code:	73423
Year Published:	2011
Web of Science® Times Cited:	5
Deposited By:	Mathematics and Physics
Deposited On:	2011-10-05
Last Modified:	2012-04-17
Downloads:	0