Abstract #2806

Jiang L, McColl R, Mason R

Deoxyhemoglobin (dHbO2) is paramagnetic and can serve as an endogenous contrast agent causing signal loss in echo planar MR images. BOLD technique has been used to evaluate physiological information in the clinic. This aim is to investigate the relationship between blood oxygenation, flow variation and intra-and extra-vessel BOLD signal change via in vitro phantom system. Experiment was performed in 4.7T scanner. Our results showed BOLD signal in vessel is sensitive to both flow and oxygenation variation. Intriguingly, a significant signal decrease was found in extra-vessel regions when oxygenation was increased. It may contribute to observations interpreted as the steal effect.