Dependence of resting-state fMRI fluctuation amplitudes on cerebral cortical orientation relative to the direction of B0 and anatomical axes

Olivia Viessmann, Klaus Scheffler, Marta Bianciardi, Lawrence L. Wald, Jonathan R. Polimeni

Abstract: Highlights•The BOLD rs-fMRI fluctuation amplitude depends on cortical orientation to B0.•Perpendicular vs. parallel orientation induces up to 70% signal bias in 1.1 mm isotropic 7T data.•Perpendicular vs. parallel orientation induces up to 11% signal bias in 2 mm isotropic 3T data.•BOLD orientation effects exist below the GM-WM border, implying vascular influence in WM.