Integrated PET/MRI scanner with oxygen-15 labeled gases for quantification of cerebral blood flow, cerebral blood volume, cerebral oxygen extraction fraction and cerebral metabolic rate of oxygen

2021 ◽  
Author(s):  
Hiroshi Ito ◽  
Hitoshi Kubo ◽  
Kazuhiro Takahashi ◽  
Ken-Ichi Nishijima ◽  
Naoyuki Ukon ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Metabolic Rate ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Cerebral Oxygen ◽  
Cerebral Metabolic Rate ◽  
Extraction Fraction

scholarly journals Effect of ephedrine and phenylephrine on brain oxygenation and microcirculation in anaesthetised patients with cerebral tumours: study protocol for a randomised controlled trial

BMJ Open ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. e018560 ◽  
Author(s):  
Klaus Ulrik Koch ◽  
Anna Tietze ◽  
Joel Aanerud ◽  
Gorm von Öettingen ◽  
Niels Juul ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Metabolic Rate ◽  
Transit Time ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Brain Oxygenation ◽  
Cerebral Metabolic Rate ◽  
Arterial Blood ◽  
Extraction Fraction

IntroductionDuring brain tumour surgery, vasopressor drugs are commonly administered to increase mean arterial blood pressure with the aim of maintaining sufficient cerebral perfusion pressure. Studies of the commonly used vasopressors show that brain oxygen saturation is reduced after phenylephrine administration, but unaltered by ephedrine administration. These findings may be explained by different effects of phenylephrine and ephedrine on the cerebral microcirculation, in particular the capillary transit-time heterogeneity, which determines oxygen extraction efficacy. We hypothesised that phenylephrine is associated with an increase in capillary transit-time heterogeneity and a reduction in cerebral metabolic rate of oxygen compared with ephedrine. Using MRI and positron emission tomography (PET) as measurements in anaesthetised patients with brain tumours, this study will examine whether phenylephrine administration elevates capillary transit-time heterogeneity more than ephedrine, thereby reducing brain oxygenation.Methods and analysisThis is a double-blind, randomised clinical trial including 48 patients scheduled for surgical brain tumour removal. Prior to imaging and surgery, anaesthetised patients will be randomised to receive either phenylephrine or ephedrine infusion until mean arterial blood pressure increases to above 60 mm Hg or 20% above baseline. Twenty-four patients were allocated to MRI and another 24 patients to PET examination. MRI measurements include cerebral blood flow, capillary transit-time heterogeneity, cerebral blood volume, blood mean transit time, and calculated oxygen extraction fraction and cerebral metabolic rate of oxygen for negligible tissue oxygen extraction. PET measurements include cerebral metabolic rate of oxygen, cerebral blood flow and oxygen extraction fraction. Surgery is initiated after MRI/PET measurements and subdural intracranial pressure is measured.Ethics and disseminationThis study was approved by the Central Denmark Region Committee on Health Research Ethics (12 June 2015; 1-10-72-116-15). Results will be disseminated via peer-reviewed publication and presentation at international conferences.Trial registration numberNCT02713087; Pre-results. 2015-001359-60; Pre-results.

scholarly journals Simultaneous and noninvasive imaging of cerebral oxygen metabolic rate, blood flow and oxygen extraction fraction in stroke mice

NeuroImage ◽  
2013 ◽  
Vol 64 ◽  
pp. 437-447 ◽  
Author(s):  
Xiao-Hong Zhu ◽  
James M. Chen ◽  
Tsang-Wei Tu ◽  
Wei Chen ◽  
Sheng-Kwei Song
Keyword(s):  
Blood Flow ◽  
Metabolic Rate ◽  
Noninvasive Imaging ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Cerebral Oxygen ◽  
Extraction Fraction

scholarly journals T2’-Imaging to Assess Cerebral Oxygen Extraction Fraction in Carotid Occlusive Disease: Influence of Cerebral Autoregulation and Cerebral Blood Volume

PLoS ONE ◽  
2016 ◽  
Vol 11 (8) ◽  
pp. e0161408 ◽  
Author(s):  
Alexander Seiler ◽  
Ralf Deichmann ◽  
Waltraud Pfeilschifter ◽  
Elke Hattingen ◽  
Oliver C. Singer ◽  
...  
Keyword(s):  
Blood Volume ◽  
Cerebral Autoregulation ◽  
Cerebral Blood Volume ◽  
Occlusive Disease ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Cerebral Oxygen ◽  
Extraction Fraction ◽  
Carotid Occlusive Disease

Cerebral Blood Flow and Cerebral Metabolic Rate of Oxygen Requirements for Cerebral Function and Viability in Humans

1985 ◽  
Vol 5 (4) ◽  
pp. 600-608 ◽  
Author(s):  
William J. Powers ◽  
Robert L. Grubb ◽  
Danielle Darriet ◽  
Marcus E. Raichle
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Metabolic Rate ◽  
Cerebral Blood Volume ◽  
Oxygen Extraction Fraction ◽  
Neurological Deficits ◽  
Regional Cerebral Blood ◽  
Cerebral Tissue ◽  
Cerebral Metabolic Rate ◽  
Regional Cerebral Blood Volume

This study was undertaken to determine the minimum CBF and CMRO2 required by the human brain to maintain normal function and viability for more than a few hours. Positron emission tomography (PET) was used to perform regional measurements in 50 subjects with varying degrees of cerebral ischemia but no evidence of infarction. There were 24 normal subjects, 24 subjects with arteriographic evidence of vascular disease of the carotid system, and two subjects with reversible ischemic neurological deficits due to cerebral vasospasm. Minimum values found in the 48 subjects with normal neurological function were 19 ml/100 g-min for regional cerebral blood flow (rCBF) and 1.3 ml/100 g-min for regional cerebral metabolic rate of oxygen (rCMRO2). Minimum values for all 50 subjects with viable cerebral tissue were 15 ml/100 g-min for rCBF and 1.3 ml/100 g-min for rCMRO2. Comparison of these measurements with values from 20 areas of established cerebral infarction in 10 subjects demonstrated that 80% (16/20) of infarcted regions had rCMRO2 values below the lower normal limit of 1.3 ml/100g-min. Measurements of rCBF, regional cerebral blood volume, and oxygen extraction fraction were less useful for distinguishing viable from infarcted tissue. These data indicate that quantitative regional measurements of rCMRO2 with PET accurately distinguish viable from nonviable cerebral tissue and may be useful in the prospective identification of patients with reversible ischemia.

scholarly journals Ephedrine versus Phenylephrine Effect on Cerebral Blood Flow and Oxygen Consumption in Anesthetized Brain Tumor Patients

2020 ◽  
Vol 133 (2) ◽  
pp. 304-317
Author(s):  
Klaus U. Koch ◽  
Irene K. Mikkelsen ◽  
Joel Aanerud ◽  
Ulrick S. Espelund ◽  
Anna Tietze ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Metabolic Rate ◽  
Oxygen Saturation ◽  
Oxygen Extraction Fraction ◽  
Cerebral Oxygen Saturation ◽  
Cerebral Oxygen ◽  
Contralateral Hemisphere ◽  
Regional Cerebral Oxygen Saturation ◽  
Cerebral Metabolic Rate

Background Studies in anesthetized patients suggest that phenylephrine reduces regional cerebral oxygen saturation compared with ephedrine. The present study aimed to quantify the effects of phenylephrine and ephedrine on cerebral blood flow and cerebral metabolic rate of oxygen in brain tumor patients. The authors hypothesized that phenylephrine reduces cerebral metabolic rate of oxygen in selected brain regions compared with ephedrine. Methods In this double-blinded, randomized clinical trial, 24 anesthetized patients with brain tumors were randomly assigned to ephedrine or phenylephrine treatment. Positron emission tomography measurements of cerebral blood flow and cerebral metabolic rate of oxygen in peritumoral and normal contralateral regions were performed before and during vasopressor infusion. The primary endpoint was between-group difference in cerebral metabolic rate of oxygen. Secondary endpoints included changes in cerebral blood flow, oxygen extraction fraction, and regional cerebral oxygen saturation. Results Peritumoral mean ± SD cerebral metabolic rate of oxygen values before and after vasopressor (ephedrine, 67.0 ± 11.3 and 67.8 ± 25.7 μmol · 100 g−1 · min−1; phenylephrine, 68.2 ± 15.2 and 67.6 ± 18.0 μmol · 100 g−1 · min−1) showed no intergroup difference (difference [95% CI], 1.5 [−13.3 to 16.3] μmol · 100 g−1 · min−1 [P = 0.839]). Corresponding contralateral hemisphere cerebral metabolic rate of oxygen values (ephedrine, 90.8 ± 15.9 and 94.6 ± 16.9 μmol · 100 g−1 · min−1; phenylephrine, 100.8 ± 20.7 and 96.4 ± 17.7 μmol · 100 g−1 · min−1) showed no intergroup difference (difference [95% CI], 8.2 [−2.0 to 18.5] μmol · 100 g−1 · min−1 [P = 0.118]). Ephedrine significantly increased cerebral blood flow (difference [95% CI], 3.9 [0.7 to 7.0] ml · 100 g−1 · min−1 [P = 0.019]) and regional cerebral oxygen saturation (difference [95% CI], 4 [1 to 8]% [P = 0.024]) in the contralateral hemisphere compared to phenylephrine. The change in oxygen extraction fraction in both regions (peritumoral difference [95% CI], −0.6 [−14.7 to 13.6]% [P = 0.934]; contralateral hemisphere difference [95% CI], −0.1 [− 12.1 to 12.0]% [P = 0.989]) were comparable between groups. Conclusions The cerebral metabolic rate of oxygen changes in peritumoral and normal contralateral regions were similar between ephedrine- and phenylephrine-treated patients. In the normal contralateral region, ephedrine was associated with an increase in cerebral blood flow and regional cerebral oxygen saturation compared with phenylephrine. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

scholarly journals Effects of Acetazolamide on Cerebral Blood Flow, Blood Volume, and Oxygen Metabolism: A Positron Emission Tomography Study with Healthy Volunteers

2001 ◽  
Vol 21 (12) ◽  
pp. 1472-1479 ◽  
Author(s):  
Hidehiko Okazawa ◽  
Hiroshi Yamauchi ◽  
Kanji Sugimoto ◽  
Hiroshi Toyoda ◽  
Yoshihiko Kishibe ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Metabolic Rate ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Capillary Blood ◽  
Emission Tomography ◽  
Positron Emission ◽  
Capillary Blood Volume

To evaluate changes in cerebral hemodynamics and metabolism induced by acetazolamide in healthy subjects, positron emission tomography studies for measurement of cerebral perfusion and oxygen consumption were performed. Sixteen healthy volunteers underwent positron emission tomography studies with15O-gas and water before and after intravenous administration of acetazolamide. Dynamic positron emission tomography data were acquired after bolus injection of H215O and bolus inhalation of15O2. Cerebral blood flow, metabolic rate of oxygen, and arterial-to-capillary blood volume images were calculated using the three-weighted integral method. The images of cerebral blood volume were calculated using the bolus inhalation technique of C15O. The scans for cerebral blood flow and volume and metabolic rate of oxygen after acetazolamide challenge were performed at 10, 20, and 30 minutes after drug injection. The parametric images obtained under the two conditions at baseline and after acetazolamide administration were compared. The global and regional values for cerebral blood flow and volume and arterial-to-capillary blood volume increased significantly after acetazolamide administration compared with the baseline condition, whereas no difference in metabolic rate of oxygen was observed. Acetazolamide-induced increases in both blood flow and volume in the normal brain occurred as a vasodilatory reaction of functioning vessels. The increase in arterial-to-capillary blood volume made the major contribution to the cerebral blood volume increase, indicating that the raise in cerebral blood flow during the acetazolamide challenge is closely related to arterial-to-capillary vasomotor responsiveness.

Sign in / Sign up

Export Citation Format

Share Document