Georgy D. Guryev^{1,2}, Athanasios G. Polimeridis^{3}, Elfar Adalsteinsson^{1,4,5}, Lawrence L. Wald^{5,6,7}, and Jacob K. White^{1}

When multicoil transmit arrays are used in high field scanners, patient-specific optimization can improve image quality and increase safety margins, particularly for patients with implants. The feasibility of performing such optimizations in real-time was demonstrated recently[5], using a combination of fast tissue mapping and voxel-based field simulation[4], but only for a single-port coil and an implant-free patient. In this abstract we describe new techniques for simulating complex coils that accelerates MARIE simulation as much as an order of magnitude, and an efficient approach to including metal implants. We demonstrate field analysis in minutes using the open-source simulator MARIE2.0.

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- E. Milshteyn et al. (Abstract for ISMRM 2019). "Individualized SAR Calculations Using Computer-Vision-Based MR Segmentation and a Fast Electromagnetic Solver"

The figure depicts the uniform volumetric expansion basis for a given pair of triangles. The coupled system is solved for the interaction between the expansion basis and the body model

The MARIE2.0 speedup over MARIE achieved several RF coil geometries and body models. The largest speedup is achieved in the case a large body model and a refined coil discretization.

The breakdown of the simulation times for the 5mm Duke body model and the 16-Leg Birdcage RF coil. From the table follows that the coupling matrix assembly becomes the most time consuming part of simulation for large models.

The breakdown of the simulation times for the 4mm Billie body model and the 16-Leg Birdcage RF coil.

The preliminary results of implant simulation. The strait conducting strip is located inside a homogeneous sphere; the system is excited with a plane wave. The lower graphs depict Electric field distribution.