Figure 2.

(A–C) Confocal-based angiograms of rat cerebral cortices, generated by phosphorescence intensity of exogenous Oxyphor R2 dye. Arterioles are outlined in red and venules are outlined in blue. Color-coded points indicate intravascular oxygen partial pressure (pO₂) measurements. (D–F) Corresponding optical coherence tomography (OCT)-based angiograms generated by scattering intensity. Scale bars: 500 μm. (G) pO₂ measurements in arteries and veins under baseline conditions, measured in 10 animals. Linear fits yielded R²=0.70 and R²=0.10 for arterioles and venules, respectively. (H) Absolute flow measurements in ascending venules under baseline homeostatic conditions, with associated quadratic fit (R²=0.65).