Global Intravascular and Local Hyperoxia Contrast Phase-Based Blood Oxygenation Measurements

Ian D. Driver¹, Samuel J. Wharton¹, Paula L. Croal¹, Richard W. Bowtell¹, Susan T. Francis¹, Penelope A. Gowland¹

The measurement of venous blood oxygenation (Yv) is important in cases where oxygen extraction fraction (OEF) may be perturbed. We assess phase-based methods for measuring Yv, either using intravascular phase of a large vein (the superior sagittal sinus in our case), or by comparing the phase distributions local to a vessel, as perturbed by hyperoxia. We measured similar Yv values using both approaches, although the hyperoxia-based method is suitable for small veins and independent of their orientation, providing localised Yv measurements. Some evidence for spatial heterogeneity in Yv was found using this method.