32‐channel 3 Tesla receive‐only phased‐array head coil with soccer‐ball element geometry

Abstract

A 32‐channel 3T receive‐only phased‐array head coil was developed for human brain imaging. The helmet‐shaped array was designed to closely fit the head with individual overlapping circular elements arranged in patterns of hexagonal and pentagonal symmetry similar to that of a soccer ball. The signal‐to‐noise ratio (SNR) and noise amplification (g‐factor) in accelerated imaging applications were quantitatively evaluated in phantom and human images and compared with commercially available head coils. The 32‐channel coil showed SNR gains of up to 3.5‐fold in the cortex and 1.4‐fold in the corpus callosum compared to a (larger) commercial eight‐channel head coil. The experimentally measured g‐factor performance of the helmet array showed significant improvement compared to the eight‐channel array (peak g‐factor 59% and 26% of the eight‐channel values for four‐ and fivefold acceleration). The performance of the arrays is demonstrated in high‐resolution and highly accelerated brain images. Magn Reson Med, 2006.