Figure 16.

Periodically rotated overlapping parallel lines with enhanced reconstruction and spiral k-space acquisition for mitigating motion artifact. Top row: The periodically rotated overlapping parallel lines with enhanced reconstruction techniques (PROPELLER or BLADE) use a combination of rectilinear and radial trajectories in each blade to correct for motion artifacts on the axial MR image (top right). Bottom row: Spiral k-space trajectories are also robust to motion because of their faster acquisition compared with conventional rectilinear sampling strategies.