Out-of-focus signal rejection for in vivo pO₂ measurements using two-photon phosphorescence lifetime microscopy

Two-photon phosphorescence lifetime microscopy has been a key tool for studying cerebral oxygenation in mice. However, the accuracy of the partial pressure of oxygen (pO 2 ) measurements is affected by out-of-focus signal. In this work, we applied reconfigurable differential aberration imaging to characterize and correct for out-of-focus signal contamination in intravascular pO 2 imaging. Our results show that signal contamination is higher in more oxygenated vessels and that it could be effectively removed using the proposed method.