Abstract #3604

Vascular-Space-Occupancy (VASO) MRI in Human Brain at 7T

Jun Hua^1,2, Craig K. Jones^1,2, Peter C. M. van Zijl^1,2

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

VASO-MRI exploits the difference between blood and tissue T1 to blood signal and measure CBV changes using residual tissue signal. At 7T, VASO-MRI faces two challenges: converging blood and tissue T1, and a large positive BOLD effect counteracting the negative VASO change. Off-resonance (>20ppm) MT effects are large in tissue but minimal in blood, which was used to magnify tissue signal while ing blood, and boost SNR by 11233% at 7T. A 3D turbo-field-echo (TFE) sequence with short TE (1.77ms) is employed to minimize the BOLD effect, and provide whole brain coverage (2mm isotropic) for VASO fMRI at 7T.