Separation of the Vascular and Tissue Contributions to the T1ρ Change Induced by Brain Activation

Tao Jin¹, Seong-Gi Kim^1,2

T1rho of tissue water is a physiological parameter sensitive to the tissue microenviroment as well as macromolecular composition and density. We recently reported an activation-induced change of T1rho in the parenchyma of the cat visual cortex. In order to investigate whether this T1rho contrast has significant extravascular contribution, we have studied the T1rho fMRI response with and without suppression of the intravascular blood using a contrast agent. We found that a majority of the T1rho change arose from the extravascular tissue.