Benedikt Andreas Poser1,2, David G. Norris1,2
1Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany; 2Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, Netherlands
The VASO sequence was recently proposed as first fMRI method capable of detecting activation related CBV changes without the need for a contrast agent. We here present a new whole-brain VASO technique based on a parallel-accelerated single-shot 3D GRASE sequence. A flow-compensated correction scheme for concomitant Maxwell gradients is introduced, and shown to be an essential feature for 3D GRASE sequences at 3T if smearing artifacts due to violation of the CPMG condition in off-resonance excitation are to be avoided. The effectiveness of the new method demonstrated in fMRI studies with visuo-motor stimulation, and a cognitive Stroop task paradigm.