S. L.
Talagala1, W-M Luh2, H. Merkle3
1NMRF, NINDS, National Institutes of
Health, Bethesda, MD, United States; 2FMRIF, NIMH, National
Institutes of Health, Bethesda, MD, United States; 3LFMI, NINDS,
National Institutes of Health, Bethesda, MD, United States
Currently,
CASL perfusion studies are performed using constant amplitude labeling pulses
to match the average blood velocity over the cardiac cycle. This can lead to
lower inversion efficiency during the high flow velocity periods. Use of
higher constant labeling RF amplitudes increase the power deposition and also
can reduce the inversion efficiency for lower velocities. In this work we
show that real-time change in labeling RF power according velocity may be
used to reduce power deposition from the labeling pulse without loss in
perfusion sensitivity. This method should be especially useful for CASL at 7T
and higher fields.