Reducing inter-voxel variability of the BOLD response with measurement of resting blood flow
Behzadi Y, Restom K, Perthen J, Liu T
The BOLD signal used in fMRI is dependent on regional differences on the cerebral blood flow (CBF), cerebral blood volume (CBV), and oxidative metabolism. Previous studies have attempted to account for the regional differences in the intensity of the BOLD response by hypercapnic normalization. In particular, studies showed that normalized BOLD signal induced by a motor task was consistent across different magnetic fields and pulse sequences. However, hypercapnic normalization involves the delivery of C02 and may be difficult to implement for select clinical subject populations. Here we investigate the use of resting CBF as a possible alternative normalization technique by first examining the dependence of the functional BOLD response on resting CBF.