Figure 1.

The 3D PCASL sequence used in this study and the timing of motion updates for optical and navigator-style updates. While using optical updates, the scan plane geometry was updated once before the first inversion module, continuously during the labeling module and once before the readout module. On the other hand, during navigator-style updates, motion was updated once before the labeling module using optical updates, simulating an MR navigator inserted during the idle time within the first inversion module. Dark blue and red bands show locations of optical and navigator-style updates, respectively. No correction was performed for the second saturation or inversion module since the inversion RF pulses in this section have a large slab thickness and the saturation band lies across the neck, which does not move rigidly with the head. The time axis was scaled non-linearly to show all gradient and RF pulses.