Validation of quantitative estimation of tissue oxygen extraction fraction and deoxygenated blood volume fraction in phantom and in vivo experiments by using MRI

2010 ◽  
Vol 63 (4) ◽  
pp. 910-921 ◽  
Author(s):  
Jan Sedlacik ◽  
Jürgen R. Reichenbach
Keyword(s):  
Blood Volume ◽  
Volume Fraction ◽  
Quantitative Estimation ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Tissue Oxygen ◽  
In Vivo Experiments ◽  
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 Improving qBOLD based measures of oxygen extraction fraction using hyperoxia-BOLD derived measures of blood volume

2020 ◽  
Author(s):  
Alan J Stone ◽  
Nicholas P Blockley
Keyword(s):  
White Matter ◽  
Blood Volume ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Transverse Relaxation Rate ◽  
Imaging Data ◽  
Bold Imaging ◽  
Extraction Fraction ◽  
Scan Time ◽  
Cortical Grey Matter

AbstractStreamlined-qBOLD (sqBOLD) is a recently proposed refinement of the quantitative BOLD (qBOLD) technique capable of producing non-invasive and quantitative maps of oxygen extraction fraction (OEF) in a clinically feasible scan time. However, sqBOLD measurements of OEF have been reported as being systematically lower than expected in healthy brain. Since the qBOLD framework infers OEF from the ratio of the reversible transverse relaxation rate (R2’) and deoxygenated blood volume (DBV), this underestimation of OEF has been largely attributed to an overestimation of DBV made using this technique.This study proposes a novel method, hyperoxia-constrained qBOLD (hqBOLD), to improve sqBOLD estimates of OEF. This method circumvents difficulties associated with inferring DBV from the qBOLD model by replacing it with a separate measurement of blood volume derived from hyperoxia-BOLD contrast. In a group of ten healthy volunteers, hqBOLD produced measurements of OEF in cortical grey matter (OEFhqBOLD = 44.7 ± 11.9 %) that were in better agreement with global oximetry measures (OEFTRUST = 40.4 ± 7.7 %), compared to sqBOLD derived measures (OEFsqBOLD = 13.1 ± 4.0 %).However, in the same group hqBOLD measures of OEF were found to be outside the physiological range in white matter regions (> 100%). By deriving maps of simulated R2’ from TRUST and hyperoxia-BOLD imaging data, the hqBOLD overestimation of OEF in white matter was hypothesised to originate from additional sources of magnetic susceptibility beyond deoxyhaemoglobin that are present in white matter.

scholarly journals Autoregulatory Vasodilation of Parenchymal Vessels is Impaired during Cerebral Vasospasm

1998 ◽  
Vol 18 (4) ◽  
pp. 419-424 ◽  
Author(s):  
Kent D. Yundt ◽  
Robert L. Grubb ◽  
Michael N. Diringer ◽  
William J. Powers
Keyword(s):  
Cerebral Blood Volume ◽  
Perfusion Pressure ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
Artery Occlusion ◽  
Aneurysm Rupture ◽  
Carotid Occlusion ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Extraction Fraction

Impaired CBF autoregulation during vasospasm after aneurysmal subarachnoid hemorrhage (SAH) could reflect impaired capacity of distal vessels to dilate in response to reduced local perfusion pressure or simply indicate that the perfusion pressure distal to large arteries in spasm is so low that vessels are already maximally dilated. Autoregulatory vasodilation can be detected in vivo as an increase in the parenchymal cerebral blood volume (CBV). Regional CBV, CBF, and oxygen extraction fraction in regions with and without angiographic vasospasm obtained from 29 positron emission tomography studies performed after intracranial aneurysm rupture were compared with data from 19 normal volunteers and five patients with carotid artery occlusion. Regional CBF was reduced compared to normal in regions from SAH patients with and without vasospasm as well as with ipsilateral carotid occlusion ( P < .0001). Regional oxygen extraction fraction was higher during vasospasm and distal to carotid occlusion than both normal and SAH without vasospasm ( P < .0001). Regional CBV was reduced compared to normal in regions with and without spasm, whereas it was increased ipsilateral to carotid occlusion ( P < .0001). These findings of reduced parenchymal CBV during vasospasm under similar conditions of tissue hypoxia that produce increased CBV in patients with carotid occlusion provide evidence that parenchymal vessels distal to arteries with angiographic spasm after SAH do not show normal autoregulatory vasodilation.

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