Peter T. While1, Larry K. Forbes1,
Stuart Crozier2
1School of Maths and Physics,
University of Tasmania, Hobart, TAS, Australia; 2School of
Information Technology and Electrical Engineering, University of Queensland,
Brisbane, QLD, Australia
Gradient
coil hot spots can lead to image distortion and coil failure. An analytic
method is presented for redesigning gradient coils with improved spatial
temperature distributions and reduced hot spot temperatures. Maximum
temperature is a non-linear constraint and a relaxed fixed point iteration
scheme is introduced to alter the coil windings iteratively and lower the hot
spot temperature. The new coil windings display a considerable improvement in
hot spot temperature, at no cost to coil performance, when compared to
equivalent minimum power x-gradient coils. The model can be adapted easily
for other geometries, thermal properties, cooling mechanisms and non-linear
constraints.