Discordant Responses to Cocaine in CBF and CBV: Implications for phMRI CMRO2 assessment
Schmidt K, Luo F, Ferris C, Duong T
Two potential confounding effects of extending fMRI CMRO2 calculation to pharmacological studies were investigated by simultaneous direct measurements of CBF and CBV in the same experimental animal. While CBF showed a monophasic increase after cocaine infusion, CBV demonstrated a biphasic response with an initial decrease in CBV followed by prolonged CBV increase. A clear CBF-CBV discordant response to cocaine administration was found during the initial period. CBF-CBV recoupled during the steady state, however, with a significant lower value in cortical and subcortical regions. Those two effects confound phMRI CMRO2 method on evaluating cerebral oxygen metabolism following cocaine administration.