Figure 2.
(a) Three-dimensional concentric ring k-space trajectory. (b) Modulation pattern resulting from a blipped concentric ring trajectory for 3 simultaneous slices. The numbers at the top indicate the slice number, where contiguous slices in the volume are numbered 1 through 39. The 20th slice is acquired at z-isocenter, assuming an axial acquisition. The top row shows the original, non-modulated, 3 simultaneous slices. The bottom row shows what the blipped modulation does to the various slices. Slice 20 is unaffected because it is acquired at z-isocenter. The blipped-EPI equivalent of slices 7 and 33 would be a simple FOV shift.