1Neurosection, Div. of MRI Research, Dept. of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
We show that contaminations from the non-steady-state inflowing blood spins in Vascular-space-occupancy (VASO) fMRI can be eliminated by combining the previously proposed magnetization reset technique with motion-sensitized crushing gradients. The magnetization reset module is a spatially nonselective saturation applied immediately after readout. The crushing gradients can be implemented with bipolar gradients in a 2D sequence such as 2D gradient echo (GRE) echo-planar-imaging (EPI), or a motion-sensitized driven equilibrium (MSDE) spin preparation module immediately before a 3D sequence such as 3D fast GRE. When performing VASO fMRI of visual stimulation, the combined technique successfully suppressed the non-steady-state blood spins.