A three-coil comparison for MR angiography

The purpose of this work was to compare intracranial magnetic resonance ang iography (MRA) image quality using three different radiofrequency coils. Th e three coil types included a reduced volume quadrature birdcage coil with endcap, a commercially available quadrature birdcage head con, and a four-e lement phased-array coil. Signal-to-noise ratio (SNR) measurements were obt ained from comparison studies performed on a uniform cylindrical phantom. M RA comparisons were performed using data acquired from 15 volunteers and ap plying a thick-slab three-dimensional time-of-night sequence. Analysis was performed using the signal difference-to-noise ratio, a quantitative measur e of the relative vascular signal. The reduced-volume endcap and phased-arr ay coils, which were designed specifically for imaging the intracranial vol ume of the head, improved the image SNR and vascular detail considerably ov er that obtained using the commercially available head coil. The endcap coi l configuration provided the best vascular signal overall, while the phased -array coil provided the best results for arteries close to the coil elemen ts. (C) 2000 Wiley-Liss, Inc.