The Impact of Dissolved Oxygen in Blood on Hyperoxia-Based BOLD Calibration

Avery J.L. Berman¹, Richard D. Hoge², G. Bruce Pike¹

In a recently published theoretical model it was predicted that paramagnetic oxygen dissolved in blood significantly contributes to a magnetic susceptibility difference between arterial blood and the surrounding tissue when its concentration in blood ishigh, such as during hyperoxia-based BOLD calibration. We present here a revised model and have re-examined the effect of dissolved oxygen on the blood-tissue susceptibility difference using our alternative formulation and compared it with published experimental data. We found a negligible change of the arterial blood-tissue susceptibility difference between hyperoxia and normoxia, resulting in signal contrast in veins and capillaries only.