Generic Whole Body MRI Simulation,
64 MHz

Model

In this study, SEMCAD X was applied to investigate issues related to EM field performance for a generic Magnetic Resonance Imaging (MRI) system with a patient inside. The MRI system consists of 16 legs, which is excited using a leg fed network, and the other metallic shielding. The high resolution whole body phantom model, consisting of more than 100 tissues, is positioned inside the MRI system. 

Simulation

The operational frequency of the MRI system is 64 MHz so the structure is not electrically large. However, the curvature and complexity of the model still requires that it is necessary to use a fine grid to resolve the structure. The minimum step for the grid is approximately 1 mm and the total grid size is 7 MCells. Since the minimum grid step is very small in terms of the wavelength the time step also becomes very small, which implies that a large number of  time steps are required for the simulation to reach steady-state. However, using the latest hardware acceleration solutions, e.g. a CIB 800, the simulation time is still less than 1 hr.

Results

Some results from the simulation are shown, including the E-field distribution in 2 slices through the phantom. Also the SAR distribution is shown passing through the center of the phantom. The B-field distribution can also easily be extracted to investigate the uniformity of the field and significant parameters like whole body, 1 g  and 10 g spatial peak averaged SAR can be extracted.