Fig. 2.

Effective translation (as a fraction of the FOV) as a function of the k-space position for (a) Fig. 1j and 1k, (b) Fig. 1l, (c) Fig. 1n and 1o and (d) Fig. 1p. As seen, if the external disturbance oscillates as a function of k-space position, e g. in cases (b), (c) and (d), ghosting will result (see corresponding images in Fig. 1). Reduced ghosting in Fig. 1p can be explained by the effective reduced frequency of oscillation of the position as a function of the k-space coordinate (compare plots (b) and (d)). Plots of rotations are omitted due to their similar appearance.