Multislice perfusion and perfusion territory imaging in humans with separate label and image coils

An arterial spin labeling technique using separate RF labeling and imaging coils was used to obtain multislice perfusion images of the human brain at 3 T. Continuous RF irradiation at a peak power of 0.3 W was applied to the carotid arteries to adiabatically invert spins. Labeling was achieved witho ut producing magnetization transfer effects since the B-1 field of the labe ling coil did not extend into the imaging region or couple significant powe r into the imaging coil, Eliminating magnetization transfer allowed the acq uisition of multislice perfusion images of arbitrary orientation. Combining surface coil labeling with a reduced RF duty cycle permitted significantly lower SAR than single coil approaches. The technique was also found to allow selective labeling of blood in either carotid, providing an assessment of the artery's perfusion territory. In n ormal subjects, these territories were well-defined and localized to the ip silateral hemisphere, (C) 1999 Wiley-Liss, Inc.