Optimal arrangement of finite element loop arrays for parallel magnetic resonance imaging in the human head at 400 MHz

Parallel magnetic resonance imaging is limited by the signal-to-noise ratio (SNR) of the MR-signal detected by an antenna array. To fully exploit the SNR of circular surface loops surrounding a spherical head phantom, we developed an optimization routine to minimize the array's noise enhancement. We optimized the position of each element and a common loop radius. As a result we show optimal configurations for 8, 16 and 32 array elements at 400 MHz with different acceleration factors. The importance of proper element alignment with regard to the acceleration direction(s) is shown by a comparison between optimal and poor positioning.