Transmit and receive FDTD modeling as a valuable tool for RF coil development: validation of simulations with in vivo torso imaging at 7 Tesla

The ability to predict both transmit and receive characteristics in vivo is an important and necessary tool for the development of coils especially at ultra high magnetic fields (UHF). Accurate simulation permits the virtual development of coils saving both human and material resources [1, 2]. This is especially important during this period where large arrays and complex geometries are being proposed to maximize parallel imaging performance [3-5], B1+ shimming flexibility [6,7] and receive sensitivity [8] while simultaneously managing local RF deposition. Finite difference time domain (FDTD) simulations can provide a wealth of information including element specific B1 and electric fields (E-fields) to determine geometry factors, evaluate B1+ shimming performance and to calculate subsequent SAR distributions. In this paper we present several examples of where simulated results compare well with experimental data in torso imaging at 7 Tesla with a focus on the prostate. Confidence in these simulations will prospectively guide the development of future RF coils and optimization strategies.