In pCASL, the blood tagged at the
end-of-labeling period is expected to contribute most to the perfusion signal due
to T1 recovery of the labeled spins. The influence on PCASL of cardiac triggering at the end-of-labeling was assessed with simulations and subsequently
applied in volunteers. Simulations predict a 9% variation in ASL-signal over
the cardiac cycle. In-vivo
measurements were unable to show the predicted effect nor a difference
in tSNR. Combining with earlier findings concerning cardiac triggering, neither triggering start- or end of labeling triggering
improves signal stability, suggesting
that cardiac triggering is not beneficial for pCASL.
