Improved k‐space trajectory measurement with signal shifting

Various techniques for k‐space trajectory measurement have been described in the literature. Self‐encoding gradient techniques are time‐consuming due to the high number of phase‐encoding steps needed. The approach with localized slices is faster, but its use apparently has not been reported in the context of high spatial resolution experiments. Signals associated with high k‐space frequencies may then reach low or even zero values, and this may result in errors in the estimate of the trajectories at the k‐space periphery. To overcome this problem without increasing the measurement duration of the localized slice method too much, a new approach is proposed in which an addition dephasing gradient applied prior to the gradient to be measured shifts the signal maximum. Magn Reson Med 58:200–205, 2007. © 2007 Wiley‐Liss, Inc.