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.