Simulation and Verification of Magnetic Field Gradient Waveforms in the Presence of a Metallic Vessel in Magnetic Resonance Imaging

We present simulation and experimental results regarding the generation of eddy currents due to switched magnetic field gradients during the use of metallic vessels in high-pressure magnetic resonance imaging (MRI) applications. The induced eddy currents result in a corruption of the applied magnetic field gradient as experienced by the object being imaged. Simulations using CST EM Studio™ have revealed the spatial distribution and temporal evolution of eddy currents, the resulting magnetic fields, and their dependence on vessel material and orientation of the applied switched magnetic field gradient. The simulation results have been compared to measured data with excellent agreement. Agreement between simulated and measured data permits increasingly sophisticated models to be developed such that simulation results reliably guide the design of improved metal vessels.