Dependence of CBV estimated from 7T Dynamic Susceptibility Contrast data on white matter tract and cortical gray matter orientation relative to B0

Previous studies have reported an orientation effect in DSC data within the white matter in which CBV estimates vary systematically with the orientation of local fiber orientation. Other studies have reported similar orientation effects in BOLD fMRI data both with respect to white-matter fiber orientation and gray-matter cortical orientation. Here we extend these findings by investigating orientation effects in gray and white matter in DSC-based CBV estimates. We find strong effects in both brain regions consistent with both groups of prior studies, corroborating previous interpretations that the observed BOLD effects in the white matter are vascular in origin.