scholarly journals Measurement of parenchymal extravascularR2* and tissue oxygen extraction fraction using multi-echo vascular space occupancy MRI at 7 T

2014 ◽  
Vol 28 (2) ◽  
pp. 264-271 ◽  
Author(s):  
Ying Cheng ◽  
Peter C. M. van Zijl ◽  
Jun Hua
Keyword(s):  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Tissue Oxygen ◽  
Vascular Space ◽  
Extraction Fraction

Abstract 153: Non-invasive Measurement of Cerebral Tissue Oxygen Extraction Fraction is Correlated with Microdialysis Brain Injury Biomarkers During Extracorporeal Cardiopulmonary Resuscitation

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_4) ◽  
Author(s):  
Tiffany S Ko ◽  
Julia Slovis ◽  
Lindsay Volk ◽  
Constantine D Mavroudis ◽  
Ryan W Morgan ◽  
...  
Keyword(s):  
Brain Injury ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Neurological Injury ◽  
Tissue Oxygen ◽  
Cerebral Tissue ◽  
Extracorporeal Cardiopulmonary Resuscitation ◽  
Glucose Content ◽  
Non Invasive ◽  
Extraction Fraction

Introduction: Extracorporeal membrane oxygenation (ECMO) assisted CPR (ECPR) can improve outcomes after prolonged or unsuccessful resuscitative efforts, but neurological injury remains common in survivors. The lack of routine neuromonitoring during ECPR and ECMO prohibits brain-targeted management to help improve neurological outcomes. In this study, we examine the association of non-invasive, frequency-domain diffuse optical spectroscopy (FD-DOS) measurements of cerebral tissue oxygen extraction fraction (OEF), an indicator of metabolic stress, with invasively collected brain injury biomarkers to explore the utility of this monitoring modality during ECPR. Hypothesis: FD-DOS measurement of cerebral OEF is positively correlated with biomarkers of brain injury (lactate-pyruvate ratio, LPR; glycerol). Methods: Cerebral OEF was continuously monitored by FD-DOS in nine pediatric swine (8-11 kg) who underwent 30-60 minutes of manual CPR, were cannulated for ECMO, and remained on ECMO for 22-24 hours. Cerebral pyruvate, lactate, glycerol and glucose content were measured from cerebral microdialysate samples collected hourly. The correlation between OEF and microdialysis parameters were assessed using a linear mixed-effects model incorporating subject-specific random slope and intercept effects. Significance was determined at p<0.05. Results: Microdialysis parameters from 192 samples were compared against non-invasive OEF values. OEF was significantly correlated with LPR (p=0.001), and relative change in glycerol (p=0.005) and glucose (p=0.020) concentrations from baseline. Conclusions: Non-invasive FD-DOS neuromonitoring of OEF demonstrated significant correlations with invasive brain injury biomarkers; increasing OEF was associated with elevated LPR and glycerol, and diminished glucose. FD-DOS detection of critical neurometabolic stress at the bedside may facilitate brain-targeted ECMO management after cardiac arrest.

scholarly journals Oxygen Extraction Fraction at Maximally Vasodilated Tissue in the Ischemic Brain Estimated from the Regional CO2 Responsiveness Measured by Positron Emission Tomography

1988 ◽  
Vol 8 (2) ◽  
pp. 227-235 ◽  
Author(s):  
Iwao Kanno ◽  
Kazuo Uemura ◽  
Schuichi Higano ◽  
Matsutaro Murakami ◽  
Hidehiro Iida ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Resting State ◽  
Emission Tomography ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Cross Point ◽  
Steady State Method ◽  
Extraction Fraction ◽  
Positron Emission ◽  
Vascular Responsiveness

The oxygen extraction fraction (OEF) at maximally vasodilated tissue in patients with chronic cerebrovascular disease was evaluated using positron emission tomography. The vascular responsiveness to changes in PaCO2 was measured by the H215O autoradiographic method. It was correlated with the resting-state OEF, as estimated using the 15O steady-state method. The subjects comprised 15 patients with unilateral or bilateral occlusion and stenosis of the internal carotid artery or middle cerebral artery or moyamoya disease. In hypercapnia, the scattergram between the OEF and the vascular responsiveness to changes in PaCO2 revealed a significant negative correlation in 11 of 19 studies on these patients, and the OEF at the zero cross point of the regression line with a vascular responsiveness of 0 was 0.53 ± 0.08 (n = 11). This OEF in the resting state corresponds to exhaustion of the capacity for vasodilation. The vasodilatory capacity is discussed in relation to the lower limit of autoregulation.

scholarly journals Quantifying the changes in oxygen extraction fraction and cerebral activity caused by caffeine and acetazolamide

2016 ◽  
Vol 37 (3) ◽  
pp. 825-836 ◽  
Author(s):  
Sagar Buch ◽  
Yongquan Ye ◽  
E Mark Haacke
Keyword(s):  
Oxygen Saturation ◽  
A Priori ◽  
Susceptibility Mapping ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Cerebral Veins ◽  
Blood Oxygen Saturation ◽  
Vascular Reserve ◽  
Extraction Fraction ◽  
Before And After

A quantitative estimate of cerebral blood oxygen saturation is of critical importance in the investigation of cerebrovascular disease. We aimed to measure the change in venous oxygen saturation (Yv) before and after the intake of the vaso-dynamic agents caffeine and acetazolamide with high spatial resolution using susceptibility mapping. Caffeine and acetazolamide were administered on separate days to five healthy volunteers to measure the change in oxygen extraction fraction. The internal streaking artifacts in the susceptibility maps were reduced by giving an initial susceptibility value uniformly to the structure-of-interest, based on a priori information. Using this technique, Yv for normal physiological conditions, post-caffeine and post-acetazolamide was measured inside the internal cerebral veins as YNormal = 69.1 ± 3.3%, YCaffeine = 60.5 ± 2.8%, and YAcet = 79.1 ± 4.0%. This suggests that susceptibility mapping can serve as a sensitive biomarker for measuring reductions in cerebro-vascular reserve through abnormal vascular response. The percentage change in oxygen extraction fraction for caffeine and acetazolamide were found to be +27.0 ± 3.8% and −32.6 ± 2.1%, respectively. Similarly, the relative changes in cerebral blood flow in the presence of caffeine and acetazolamide were found to be −30.3% and + 31.5%, suggesting that the cerebral metabolic rate of oxygen remains stable between normal and challenged brain states for healthy subjects.

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