Measuring individual vein and artery BOLD responses to visual stimuli in humans with multi-echo single-vessel functional MRI at 7T

Here we apply single-vessel fMRI techniques to evaluate BOLD and non-BOLD contributions within individual arteries and veins. First we identified individual vessels from inflow effects in a small set of slices, and distinguished arteries and veins on the basis of their T2* decay. Then we applied a high-inplane-resolution multi-echo single-vessel fMRI approach to examine fMRI responses within these vessels. We find evidence for both BOLD and potentially non-BOLD responses within arteries, suggesting that in some cases BOLD may capture arterial responses BOLD which may be more neuronally specific (in space and time) than effects from downstream veins.