A Potential Better Estimation of Penumbra using T2*-Weighted fMRI of Oxygen Challenge

Qiang Shen^1,2, Shiliang Huang¹, Fang Du¹, Timothy Q. Duong^1,2

The identification of ischemic penumbra and the distinction of this potentially reversible condition from irreversibly damaged tissue is of utmost importance for the initiation of treatment strategies. Although diffusion/perfusion MRI mismatch has been used to be an estimation of penumbra, it has been demonstrated overestimate penumbra. In this study, T2* weighted fMRI responses of stroke rats to oxygen challenge (OC) were investigated. DWI/PWI mismatch region showed significant higher than normal T2* weight signal increase. Tissues with higher than normal T2* weighted signal increase during OC and spatially around the ischemic core could be a better estimation of penumbra.