Fast- k z three-dimensional tailored radiofrequency pulse for reduced B 1 inhomogeneity

Abstract

This article presents a small-flip-angle, three-dimensional tailored RF pulse that excites thin slices with an adjustable quadratic in-plane spatial variation. The quadratic spatial variation helps to compensate for the loss in image uniformity using a volume coil at 3 T due to the wavelike properties of the RF field. The pulse is based on a novel “fast- k z ” design that uses a series of slice-select subpulses along k z and phase encoding “blips” along k x – k y . The method is demonstrated by acquiring a series of 5-mm-thick T 2 -weighted images of the human brain at 3 T using pulses 4.8 ms in length with a 45 ° flip angle. Magn Reson Med, 2006. © 2006 Wiley-Liss, Inc.