Abstract
Purpose
To obtain cerebral perfusion territories of the left, the right, and the posterior circulation in humans with high signal‐to‐noise ratio (SNR) and robust delineation.
Materials and Methods
Continuous arterial spin labeling (CASL) was implemented using a dedicated radio frequency (RF) coil, positioned over the neck, to label the major cerebral feeding arteries in humans. Selective labeling was achieved by flow‐driven adiabatic fast passage and by tilting the longitudinal labeling gradient about the Y‐axis by θ = ± 60°.
Results
Mean cerebral blood flow (CBF) values in gray matter (GM) and white matter (WM) were 74 ± 13 mL · 100 g^−1^ · minute^−1^ and 14 ± 13 mL · 100 g^−1^ · minute^−1^, respectively (N = 14). There were no signal differences between left and right hemispheres when θ = 0° (P > 0.19), indicating efficient labeling of both hemispheres. When θ = +60°, the signal in GM on the left hemisphere, 0.07 ± 0.06%, was 92% lower than on the right hemisphere, 0.85 ± 0.30% (P < 1 × 10^−9^), while for θ = −60°, the signal in the right hemisphere, 0.16 ± 0.13%, was 82% lower than on the contralateral side, 0.89 ± 0.22% (P < 1 × 10^−10^). Similar attenuations were obtained in WM.
Conclusion
Clear delineation of the left and right cerebral perfusion territories was obtained, allowing discrimination of the anterior and posterior circulation in each hemisphere. J. Magn. Reson. Imaging 2008;27:970–977. © 2008 Wiley‐Liss, Inc.