Silke Maria Lechner1,2, Timothy J. Hollis3,
Hans-Joachim Bungartz2, Bruce C. Amm4, Guido Kudielka1,
Mika W. Vogel1
1GE Global Research Europe, Garching,
Germany; 2Technische Universitt Mnchen, Garching, Germany; 3GE
Medical Systems, Oxford, United Kingdom; 4GE Global Research,
Niskayuna, NY, United States
The
use of computer assisted magnetic resonance imaging simulation strongly
supports the design of new gradient hardware as it allows the prediction of
gradient non-linearity or other distortion sources on image quality. This
work utilizes finite element method simulations of a uni-planar gradient set
to analyze and visualize the created transient eddy currents. Therefore,
typical eddy current origins, such as thermal shield and cryostat, but also
the included cooling tubes of the planar gradient set are investigated. Eddy
current amplitudes and timing constants are presented for aluminum, stainless
steel and copper, where interestingly, the eddy currents induced in copper
cooling tubes are as strong as the induced currents in the warm bore.