scholarly journals Cerebellum as the Normal Reference for the Detection of Increased Cerebral Oxygen Extraction

2010 ◽  
Vol 30 (10) ◽  
pp. 1767-1776 ◽  
Author(s):  
Thomas T Jiang ◽  
Tom O Videen ◽  
Robert L Grubb ◽  
William J Powers ◽  
Colin P Derdeyn
Keyword(s):  
Stroke Risk ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Reference Region ◽  
Positron Emission Tomographic ◽  
Extraction Fraction ◽  
Kaplan Meier ◽  
Positron Emission ◽  
Hemodynamic Impairment ◽  
A Prospective Study

Hemispheric ratios of oxygen extraction fraction (OEF), a proven methodology for the detection of severe hemodynamic impairment and stroke risk, are not sensitive for detecting bilateral hemispheric increases in OEF. The aim of this study was to investigate the use of cerebellum as the reference normal. We analyzed positron emission tomographic (PET) measurements of count-based OEF and clinical data from 57 patients with unilateral atherosclerotic carotid occlusion and 13 controls enrolled in a prospective study of stroke risk. The ipsilateral, contralateral, and total cerebellum were each evaluated as possible reference regions, and the ratios of the middle cerebral artery (MCA) hemispheric OEF counts against those in each reference region were determined. A statistically significant correlation ( P<0.0001) was observed with all three MCA-to-cerebellar ratios when compared with the gold standard of ipsilateral-to-contralateral MCA hemispheric ratio. Kaplan–Meier analyses showed all MCA-to-cerebellar ratios to be predictive of stroke. By using the total cerebellum method, 7 strokes were found to have occurred in 20 patients with increased OEF ( P=0.0007), compared with 7 strokes out of 16 patients with elevated OEF using the ipsilateral or contralateral cerebellum methods ( P<0.0001). These methods may be useful for categorizing the hemodynamic status of patients with bilateral cerebral occlusive diseases, including atherosclerosis and moyamoya, to determine the association with the risk of subsequent stroke.

Abstract TMP38: Diminished Cortical Thickness and Increased Oxygen Extraction Fraction in Moyamoya Disease

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
John Lee ◽  
James Sagar ◽  
Gregory Zipfel ◽  
Allyson Zazulia ◽  
Colin Derdeyn
Keyword(s):  
Cortical Thickness ◽  
Cortical Neurons ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Down Regulation ◽  
Extraction Fraction ◽  
Positron Emission ◽  
Hemodynamic Impairment ◽  
Revascularization Surgery ◽  
Moyamoya Phenomenon

PURPOSE: Chronic hemodynamic impairment may lead to reduced cortical thickness, perhaps related to metabolic down-regulation in cortical neurons. The purpose of this study was to determine whether hemodynamic impairment correlated with diminished cortical thickness in patients with idiopathic moyamoya phenomenon. METHODS: The study was a retrospective analysis of a prospective, blindly-adjudicated, multicenter patient cohort. Inclusion criteria required moyamoya phenomenon diagnosed by catheter angiography and presumed idiopathic basal arterial occlusive disease. Oxygen extraction fraction (OEF) was measured using positron emission tomography (PET). Hemodynamic impairment was determined by comparing the OEF of middle cerebral artery territories to cerebellar regions and to normal control subjects. MR imaging was obtained concurrently with PET, within several hours, and cortical thickness estimates were made with Freesurfer (http://surfer.nmr.mgh.harvard.edu). OEF measurements were then compared to cortical thickness measurements. RESULTS: Adequate MR studies were available for 40 subjects. Mean age was 44 years. Eleven were male. Thirty-one had bilateral disease. Three had increased OEF in both hemispheres and four had unilateral increased OEF. Three patients underwent revascularization surgery during follow-up. Robust linear regression of relative cortical thickness to relative OEF is shown below: the slope was -0.02693 (-0.03002, -0.02384), the intercept was 1.022 (1.019, 1.025) at 95% confidence. Pearson’s R-square was 0.9648. CONCLUSIONS: Chronic hemodynamic impairment may be associated with reduced cortical thickness. This may reflect reversible down-regulation or irreversible subclinical ischemic injury. Supported by NINDS RO1 NS051631, 1 UL1 RR024992-01, 1 TL1 RR024995-01 and 1 KL2 RR 024994-01 from the National Center for Research Resources (NCRR).

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.

Validation of T 2 ‐based oxygen extraction fraction measurement with 15 O positron emission tomography

2020 ◽  
Vol 85 (1) ◽  
pp. 290-297
Author(s):  
Dengrong Jiang ◽  
Shengwen Deng ◽  
Crystal G. Franklin ◽  
Michael O'Boyle ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Emission Tomography ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Extraction Fraction ◽  
Positron Emission ◽  
Fraction Measurement

scholarly journals Hemodynamics and oxygen extraction in chronic large artery steno-occlusive disease: Clinical applications for predicting stroke risk

2017 ◽  
Vol 38 (9) ◽  
pp. 1584-1597 ◽  
Author(s):  
Colin P Derdeyn
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Carotid Artery ◽  
Stroke Risk ◽  
Arterial Stenosis ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Large Artery ◽  
Extraction Fraction ◽  
Hemodynamic Assessment

Depending on the adequacy of collateral sources of blood flow, arterial stenosis or occlusion may lead to reduced perfusion pressure and ultimately reduced blood flow in the distal territory supplied by that vessel. There are two well-defined compensatory mechanisms to reduced pressure or flow – autoregulatory vasodilation and increased oxygen extraction fraction. Other changes, such as metabolic downregulation, are likely. The positive identification of autoregulatory vasodilation and increased oxygen extraction fraction in humans is an established risk factor for future ischemic stroke in some disease states such as atherosclerotic carotid stenosis and occlusion. The mechanisms by which ischemic stroke may occur are not clear, and may include an increased vulnerability to embolic events. The use of hemodynamic assessment to identify patients with occlusive vasculopathy at an increased risk for stroke is very appealing for several different patient populations, such as those with symptomatic intracranial atherosclerotic disease, moyamoya phenomenon, complete internal carotid artery occlusion, and asymptomatic cervical carotid artery stenosis. While there is very good data for stroke risk prediction in some of these groups, no intervention based on these tools has been proven effective yet. In this manuscript, we will review these topics above and identify areas for future research.

scholarly journals Measurement of End-Capillary Po2 with Positron Emission Tomography

1988 ◽  
Vol 8 (3) ◽  
pp. 403-410 ◽  
Author(s):  
N. M. Alpert ◽  
R. B. Buxton ◽  
J. A. Correia ◽  
R. M. Katz ◽  
R. H. Ackerman
Keyword(s):  
Positron Emission Tomography ◽  
Oxygen Saturation ◽  
Normal Subjects ◽  
Oxygen Metabolism ◽  
Emission Tomography ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Protein Levels ◽  
Extraction Fraction ◽  
Positron Emission

The analysis of positron emission tomography measurements of oxygen metabolism has been extended to provide a quantitative estimate of end-capillary Po2. The principle of this extension rests on the idea that the oxygen extraction fraction can be used to calculate the end-capillary oxygen saturation of the blood. The relation between oxygen saturation and Po2 is obtained through the oxygen dissociation curve. Our studies show that in addition to the local oxygen extraction fraction, arterial Po2 and pH values are needed in the calculation, whereas fairly large variations in factors such as Pco2, hematocrit, hemoglobin, and plasma protein levels have little or no effect. Rough estimates of end-capillary Po2 can be made using standard o2 dissociation nomograms. Blood gas and acid-base properties of blood have been known for decades, making it possible to account accurately for individual differences that may be encountered when studying patients. Measurements in nine normal subjects yielded a mean end-capillary Po2 value of 31.2 mm Hg. The ability to make a quantitative visualization of altered patterns of end-capillary Po2 provides an additional dimension to the investigation of stroke disease and tumor metabolism.

Improved Cerebral Perfusion and Metabolism after Stenting for Basilar Artery Stenosis: Technical Case Report

Neurosurgery ◽  
2001 ◽  
Vol 48 (6) ◽  
pp. 1386-1392 ◽  
Author(s):  
Naoyuki Uchiyama ◽  
Shinya Kida ◽  
Takuya Watanabe ◽  
Junkoh Yamashita ◽  
Osamu Matsui
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Basilar Artery ◽  
Cerebral Perfusion ◽  
Artery Stenosis ◽  
Oxygen Extraction Fraction ◽  
Positron Emission Tomographic ◽  
Extraction Fraction ◽  
Positron Emission ◽  
Basilar Artery Stenosis

Abstract OBJECTIVE Recent advances in stent technology have allowed the introduction of more flexible stents that may be tracked more easily in the intracranial vessels. We present a patient with improved cerebral blood flow and metabolism as assessed by positron emission tomography after stent-assisted angioplasty for symptomatic basilar artery stenosis. CLINICAL PRESENTATION A 62-year-old man, who had undergone left superficial temporal artery to middle cerebral artery bypass surgery for left internal carotid artery occlusion 10 years previously, presented with dizziness, blurred vision, and memory disturbance. Angiography revealed severe stenosis of the proximal basilar artery. Positron emission tomographic scans revealed decreased cerebral blood flow associated with increased oxygen extraction fraction in the entire brain, particularly in the posterior circulation and the left middle cerebral artery territory. Despite medical treatment, the patient experienced worsening visual disturbance and right-sided motor weakness. INTERVENTION Ticlopidine and aspirin were used as antiplatelet agents. In addition, we used argatroban, which is a direct thrombin inhibitor, as an anticoagulant during the procedure. Predilation with a coronary artery balloon was performed, followed by placement of a GFX 3- by 8-mm stent (Arterial Vascular Engineering, Santa Rosa, CA), with excellent angiographic results. The patient made a good neurological recovery, and the postoperative positron emission tomographic scan demonstrated increases in both cerebral blood flow and cerebral metabolic rate of oxygen with a normalization of oxygen extraction fraction. CONCLUSION Stent-assisted angioplasty can provide a favorable clinical course as well as improved cerebral perfusion and metabolism for a patient with basilar artery stenosis. Long-term follow-up data and additional clinical experience are required to assess the durability of this approach.

scholarly journals Analysis of Some Errors in the Measurement of Oxygen Extraction and Oxygen Consumption by the Equilibrium Inhalation Method

1985 ◽  
Vol 5 (4) ◽  
pp. 591-599 ◽  
Author(s):  
John A. Correia ◽  
Nathaniel M. Alpert ◽  
Richard B. Buxton ◽  
Robert H. Ackerman
Keyword(s):  
Systematic Errors ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Emission Computed Tomography ◽  
Arterial Blood ◽  
Extraction Fraction ◽  
Positron Emission ◽  
Computed Tomography Scanning ◽  
Subject Motion ◽  
Tomography Scanning

Some sources of error in the equilibrium inhalation method for the measurement of oxygen extraction fraction and CMRO2 by positron emission computed tomography scanning have been evaluated by computer simulation. Emphasis has been placed on errors that have not been thoroughly studied in past work. These include effects of random statistical errors, systematic errors in arterial blood radioactivity concentrations, and errors due to perturbations of the equilibrium state, to tissue inhomogeneity, and to subject motion.

scholarly journals Oxygen extraction fraction measurement using quantitative susceptibility mapping: Comparison with positron emission tomography

2015 ◽  
Vol 36 (8) ◽  
pp. 1424-1433 ◽  
Author(s):  
Kohsuke Kudo ◽  
Tian Liu ◽  
Toshiyuki Murakami ◽  
Jonathan Goodwin ◽  
Ikuko Uwano ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Normal Subjects ◽  
Susceptibility Mapping ◽  
Emission Tomography ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Inversion Method ◽  
Quantitative Susceptibility Mapping ◽  
Extraction Fraction ◽  
Positron Emission

The purposes of this study are to establish oxygen extraction fraction (OEF) measurements using quantitative susceptibility mapping (QSM) of magnetic resonance imaging (MRI), and to compare QSM–OEF data with the gold standard 15O positron emission tomography (PET). Twenty-six patients with chronic unilateral internal carotid artery or middle cerebral artery stenosis or occlusion, and 15 normal subjects were included. MRI scans were conducted using a 3.0 Tesla scanner with a three-dimensional spoiled gradient recalled sequence. QSM images were created using the morphology-enabled dipole inversion method, and OEF maps were generated from QSM images using extraction of venous susceptibility induced by deoxygenated hemoglobin. Significant correlation of relative OEF ratio to contra-lateral hemisphere between QSM–OEF and PET–OEF was observed (r = 0.62, p < 0.001). The local (intra-section) correlation was also significant (r = 0.52, p < 0.001) in patients with increased PET–OEF. The sensitivity and specificity of OEF increase in QSM was 0.63 (5/8) and 0.89 (16/18), respectively, in comparison with PET. In conclusion, good correlation was achieved between QSM–OEF and PET–OEF in the identification of elevated OEF in affected hemispheres of patients with unilateral chronic steno-occlusive disease.

Abstract TMP93: Elevated Oxygen Extraction Fraction Measured With Noninvasive MRI may be Discriminatory for Stroke Risk in Adults With Sickle Cell Anemia

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Lori C Jordan ◽  
Melissa Gindville ◽  
Allison Scott ◽  
Megan K Strother ◽  
Adetola Kassim ◽  
...  
Keyword(s):  
Linear Regression ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Stroke Risk ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Extraction Fraction ◽  
Clinical Impairment ◽  
Mean Differences ◽  
Oxygen Carrying Capacity

Introduction: No screening procedures exist for evaluating stroke risk in adults with sickle cell anemia (SCA). Reduced oxygen carrying capacity is present in SCA, which may initially be compensated for by an increase in cerebral blood flow (CBF) and then by increased oxygen extraction fraction (OEF). Hypothesis: OEF and CBF can be measured noninvasively and reproducibly with MRI using clinically-available equipment in adults with SCA; elevated OEF provides added discriminatory capacity for clinical impairment relative to vasculopathy extent and CBF alone. Methods: Structural, CBF-weighted, and MRA imaging, together with a noninvasive OEF-weighted T 2 -relaxation-under-spin-tagging (TRUST)-MRI method was applied in SCA adults (n=26) and race and age-matched controls (n=11). A Kruskal-Wallis test was applied to evaluate mean differences between SCA and control parameters. Linear regression assessed how elevated OEF correlated with increasing clinical impairment defined by presence of infarct, vasculopathy, or use of regular blood transfusions for SCA. Results: OEF had high reproducibility within the same scan session, n=37 (ICC = 0.989). Whole-brain OEF and CBF were increased in SCA adults (OEF=0.46±0.08; CBF=52.4±8.3 ml/100g/min) versus controls (OEF=0.35±0.06; CBF=43.6±5.1 ml/100g/min). Hematocrit and OEF were inversely correlated (R 2 =0.72; p<0.01). Linear regression revealed a stronger relationship of OEF than CBF with clinical impairment. In SCA adults without impairment (n=12) CBF and OEF have an inverse relationship (R 2 =0.41; p=0.01, Fig. 1A) but with clinical impairment (infarct, vasculopathy or severe pain requiring regular transfusions, n=14) CBF and OEF become uncoupled (R 2 =0.08; p=0.16; Fig. 1B) as CBF may not be able to increase further and may plateau or decline. Conclusion: TRUST-MRI OEF is a rapid, reproducible measure. OEF shows promise as screening tool for hemodynamic impairment and stroke risk in adults with SCA.

Sign in / Sign up

Export Citation Format

Share Document