Motivation: In patients with ischemic stroke, ischemic tissue reversal after reperfusion therapy has been studied structurally, but metabolic changes have not been widely researched. Goal(s): Assess the ability of a recently developed algorithm to quantify oxygen extraction fraction in ischemic tissue that reverses and what does not reverse. Approach: Using multi-echo gradient images, oxygen extraction fraction and magnetic susceptibility maps were generated for 26 ischemic stroke patients. Values were extracted respectively at 24 to 72 hours in the ischemic tissue that reversed and tissue that did not. Results: Significant differences in oxygen extraction were observed in tissue that reversed versus tissue that did not. Impact: Differentiating oxygen extraction fraction values in ischemic tissue at an early stage of ischemic stroke can potentially inform neuroprotection strategies for clinicians to reduce post-reperfusion secondary injury.