Figure 1.
Pulse sequence diagram for (A) continuous arterial spin labeling (cASL) and (B) inversion recovery (IR)-cASL. Inversion pulse for the background suppression is transmitted via the brain coil on the first radiofrequency (RF) channel. The ASL is transmitted via a separate neck coil on the second RF channel. The inversion delay TI is the sum of labeling duration (LD) and post-labeling delay (PLD), half the inversion pulse length and half of the excitation pulse length. The pre-delay is used for magnetization to return to equilibrium. Image acquisition uses gradient-echo echo-planar imaging.