Plot of oxygen saturation (sO2) over time in the left (pink) and right (orange) cortical and subcortical hemisphere ROIs while restoring breathed oxygen to 100% from 7.5% post ischemia/hypoxia for stroke induction. Ultrasound (top) and photoacoustic (bottom) coronal images in the right panel show a frame of mouse brain post ischemia/hypoxia. The red, white and blue color represents a parametric map of oxygen saturation. The right hemisphere does not fully recover sO2 levels post-reperfusion/normoxia that are shown in the left hemisphere, indicating a cerebral infarct, especially in cortical and subcortical areas.