Arteriolar Oxygen Saturation, Cerebral Blood Flow, and Retinal Vessel Diameters

Ophthalmology ◽  
2008 ◽  
Vol 115 (5) ◽  
pp. 887-892 ◽  
Author(s):  
Frank Jan de Jong ◽  
Meike W. Vernooij ◽  
M. Kamran Ikram ◽  
M. Arfan Ikram ◽  
Albert Hofman ◽  
...  
2016 ◽  
Vol 37 (3) ◽  
pp. 902-913 ◽  
Author(s):  
Thomas Alderliesten ◽  
Jill B De Vis ◽  
Petra MA Lemmers ◽  
Jeroen Hendrikse ◽  
Floris Groenendaal ◽  
...  

Although near-infrared spectroscopy is increasingly being used to monitor cerebral oxygenation in neonates, it has a limited penetration depth. The T2-prepared Blood Imaging of Oxygen Saturation (T2-BIOS) magnetic resonance sequence provides an oxygen saturation estimate on a voxel-by-voxel basis, without needing a respiratory calibration experiment. In 15 neonates, oxygen saturation measured by T2-prepared blood imaging of oxygen saturation and near-infrared spectroscopy were compared. In addition, these measures were compared to cerebral blood flow and venous oxygen saturation in the sagittal sinus. A strong linear relation was found between the oxygen saturation measured by magnetic resonance imaging and the oxygen saturation measured by near-infrared spectroscopy ( R2 = 0.64, p < 0.001). Strong linear correlations were found between near-infrared spectroscopy oxygen saturation, and magnetic resonance imaging measures of frontal cerebral blood flow, whole brain cerebral blood flow and venous oxygen saturation in the sagittal sinus ( R2 = 0.71, 0.50, 0.65; p < 0.01). The oxygen saturation obtained by T2-prepared blood imaging of oxygen saturation correlated with venous oxygen saturation in the sagittal sinus ( R2 = 0.49, p = 0.023), but no significant correlations could be demonstrated with frontal and whole brain cerebral blood flow. These results suggest that measuring oxygen saturation by T2-prepared blood imaging of oxygen saturation is feasible, even in neonates. Strong correlations between the various methods work as a cross validation for near-infrared spectroscopy and T2-prepared blood imaging of oxygen saturation, confirming the validity of using of these techniques for determining cerebral oxygenation.


2015 ◽  
Vol 36 (6) ◽  
pp. 1046-1058 ◽  
Author(s):  
Mark B Vestergaard ◽  
Ulrich Lindberg ◽  
Niels Jacob Aachmann-Andersen ◽  
Kristian Lisbjerg ◽  
Søren Just Christensen ◽  
...  

The aim of the present study was to examine changes in cerebral metabolism by magnetic resonance imaging of healthy subjects during inhalation of 10% O2 hypoxic air. Hypoxic exposure elevates cerebral perfusion, but its effect on energy metabolism has been less investigated. Magnetic resonance imaging techniques were used to measure global cerebral blood flow and the venous oxygen saturation in the sagittal sinus. Global cerebral metabolic rate of oxygen was quantified from cerebral blood flow and arteriovenous oxygen saturation difference. Concentrations of lactate, glutamate, N-acetylaspartate, creatine and phosphocreatine were measured in the visual cortex by magnetic resonance spectroscopy. Twenty-three young healthy males were scanned for 60 min during normoxia, followed by 40 min of breathing hypoxic air. Inhalation of hypoxic air resulted in an increase in cerebral blood flow of 15.5% ( p = 0.058), and an increase in cerebral metabolic rate of oxygen of 8.5% ( p = 0.035). Cerebral lactate concentration increased by 180.3% ([Formula: see text]), glutamate increased by 4.7% ([Formula: see text]) and creatine and phosphocreatine decreased by 15.2% ( p[Formula: see text]). The N-acetylaspartate concentration was unchanged ( p = 0.36). In conclusion, acute hypoxia in healthy subjects increased perfusion and metabolic rate, which could represent an increase in neuronal activity. We conclude that marked changes in brain homeostasis occur in the healthy human brain during exposure to acute hypoxia.


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