Novel Modified 3D Shepp-Logan Phantom Model for Simulation of MRI Radiofrequency Coil Design

Because radiofrequency (RF) coils used in magnetic resonance imaging (MRI) are specific for given regions of interest in the human head (HH), it is necessary to adjust the capacitance when setting the resonance frequency of MRI. Simulation-based development can reduce the number of components and manufacturing processes, but to obtain the same conditions as in the actual HH when RF coils are loaded, it is necessary to execute simulation of the head model under loading conditions. The HH model and spherical model are commonly reported for modeling the HH. In simulation, the HH model requires long calculation time because of its complicated shape. On the other hand, the calculated resonance characteristics of a spherical model are significantly different from those of the HH model, because the spherical model is oversimplified. We designed a new HH model by modifying the 3D Shepp-Logan Phantom model and evaluated its performance using a high frequency electromagnetic field simulator. Using our new head model in simulation, the approximate resonant frequency of the RF coil was calculated at 1/6 the calculation time of that when using the HH model, and the actual loading condition of the HH was reproduced.