SENSE optimization of a transceive surface coil array for MRI at 4 T.

Parallel imaging (PI) techniques employ the use of multiple radiofrequency (RF) channels to transmit and/or receive the NMR signal. In the current study we use a finite difference time domain (FDTD) method to simulate the electromagnetic fields of a RF coil array operating in transmit-receive (transceive) mode and receive-only mode. Optimization of these configurations for PI is studied as well. Our results suggest that a coil array can effectively be used for transceive or receive-only PI techniques. For a head coil configuration, the sensitivity encoding (SENSE) optimized coil array gap size and PI acceleration factor for MRI are shown to be a function of the physiological-to-intrinsic-noise ratio (PhINR) with a much stronger dependence on acceleration factor than gap size. The results provide a means to optimize any PI sequence by varying the acceleration factor based on the measured PhINR. In addition, an example design for an eight-element transceive coil array for heads at 4 T is given.