David Dongsuk Shin1, Ho-Ling Liu2, Eric C Wong1, Thomas T Liu1
1Center for Functional MRI, University of California, San Diego, La Jolla, CA, United States; 2Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taiwan
Background suppression (BGS) of static tissue can be effective for reducing structural and physiological noise and improving SNR in arterial spin labeling. However, BGS leads to a reduction in quantitative CBF estimates in a manner that has not yet been accurately predicted with theory. To address this issue, CBF estimates obtained with BGS are typically compensated using an empirically determined global scaling factor. We show that the BGS scaling factor varies across subjects and exhibits a dependence on baseline CBF. As a result, the use of a global scaling factor can lead to substantial errors in quantitative CBF estimates.