Philipp Amrein1, Feng Jia1, Sebastian Littin1, and Maxim Zaitsev1
1Dept.of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany
1Dept.of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany
In the context of the development of a high power MR
diffusion probe for the human breast, a computer model for thermal
simulation was created that allows
evaluation of different duty cycles and current strengths. The simulated
results show reasonable agreement with experimental data.
Comparison between simulated (left) and measured (middle) surface temperature after 6min permanent diffusion encoding with a b value of 101735 mm²/s. (Imax=100A,IEff≈50A, tR=200ms). Image of the actual coil (right). Note that left side of actual coil is not included in simulation since it does not contain any thermal active components.
Example for time dependency of the
current in the diffusion weighted local gradient coil. The red line indicates the corresponding effective current of the sequence which would emit the same amount of power within the coil. Sequence parameters are: tR=2500ms, Slew-rate=2000T/s, Gradient-Efficiency=300mT/m/A, b-values ~ 3280s/mm², 14700s/mm², 74900s/mm²
