Fig 3:

In a manner that bears resemblance to the PROPELLER acquisition scheme, the k_y-k_z plane was covered using a series of rotated blades, e.g., see green rectangle. The acquisition of each blade was accelerated using a non-linear subsampling scheme. Because all blades combine at the center the overall effect was to oversample the central region, thus providing resilience in the presence of motion. By oversampling the center while subsampling the edges, the net result was an acceleration factor of roughly 1.55-fold compared to a full Cartesian sampling. The grayscale bar shows the overall sampling density of the k-space acquisition.