FIG. 1.

3D stack-of-rings pulse sequence. 2D k-space is sampled with N uniformly spaced concentric rings (a), where sinusoidal gradients are designed for the outermost ring (b) and then scaled down to acquire one ring after each RF excitation pulse (d). Slice encoding gradients (c) are implemented for 3D spatial coverage. A time-efficient retracing design is used to acquire each ring through multiple revolutions (b). Similar to multi-echo acquisitions, each revolution Rev_m captures the image at a different time t_m to enable fat/water separation (m = 1, 2, 3).