Spatial distribution of flow and oxygenation in the cerebral venous drainage system

PurposeTo investigate the venous oxygenation and flow in the brain, and determine how they might change under challenged states. Materials and MethodsEight healthy human subjects (24-37 years) were studied. T-2-relaxation under spin tagging (TRUST) magnetic resonance imaging (MRI) and phase-contrast MRI were performed to measure venous oxygenation and venous blood flow, respectively, in the superior sagittal sinus (SSS), the straight sinus (SS), and the internal jugular veins (IJVs). Venous oxygenation was assessed at room air (0.03%CO2, 21%O-2) and under hyperoxia (O%CO2, 95%O-2, and 5%N-2) conditions. Venous blood flow was assessed at room air and under hypercapnia (5%CO2, 21%O-2, and 74%N-2) conditions. Whole-brain blood flow was also measured at the four feeding arteries of the brain using phase-contrast MRI. The changes in venous oxygenation and blood flow from room air to hyperoxia or hypercapnia conditions were tested using paired t-tests. ResultsVenous oxygenation in the SSS, the SS, and the IJVs was 614%, 644%, and 624%, respectively, at room air, and increased to 703% (P < 0.01 compared to room air), 71 +/- 5% (P=0.59), and 68 +/- 5% (P < 0.05) under hyperoxic condition. The SSS, SS, and IJV drained 46 +/- 9%, 16 +/- 4%, and 79 +/- 1% of whole-brain blood flow, respectively, and this flow distribution did not change under hypercapnic condition (P > 0.5). ConclusionThe results found in this study provide insight into the venous oxygenation and venous flow distribution and its heterogeneity among different venous structures. Level of Evidence: 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:1091-1098.