All Outputs (22)

Cortical oxygen extraction fraction using quantitative BOLD MRI and cerebral blood flow during vasodilation (2023)
Journal Article

Introduction: We aimed to demonstrate non-invasive measurements of regional oxygen extraction fraction (OEF) from quantitative BOLD MRI modeling at baseline and after pharmacological vasodilation. We hypothesized that OEF decreases in response to vas... Read More about Cortical oxygen extraction fraction using quantitative BOLD MRI and cerebral blood flow during vasodilation.

Modelling spatiotemporal dynamics of cerebral blood flow using multiple-timepoint arterial spin labelling MRI (2023)
Journal Article

Introduction: Cerebral blood flow (CBF) is an important physiological parameter that can be quantified non-invasively using arterial spin labelling (ASL) imaging. Although most ASL studies are based on single-timepoint strategies, multi-timepoint app... Read More about Modelling spatiotemporal dynamics of cerebral blood flow using multiple-timepoint arterial spin labelling MRI.

Quantitative chemical exchange saturation transfer imaging of nuclear overhauser effects in acute ischemic stroke (2022)
Journal Article

Purpose: In chemical exchange saturation transfer imaging, saturation effects between (Formula presented.) 2 to (Formula presented.) 5 ppm (nuclear Overhauser effects, NOEs) have been shown to exhibit contrast in preclinical stroke models. Our previo... Read More about Quantitative chemical exchange saturation transfer imaging of nuclear overhauser effects in acute ischemic stroke.

Study Protocol: The Heart and Brain Study (2021)
Journal Article

Background: It is well-established that what is good for the heart is good for the brain. Vascular factors such as hypertension, diabetes, and high cholesterol, and genetic factors such as the apolipoprotein E4 allele increase the risk of developing... Read More about Study Protocol: The Heart and Brain Study.

Model-based Bayesian inference of brain oxygenation using quantitative BOLD (2019)
Journal Article

© 2019 The Authors Streamlined Quantitative BOLD (sqBOLD) is an MR technique that can non-invasively measure physiological parameters including Oxygen Extraction Fraction (OEF) and deoxygenated blood volume (DBV) in the brain. Current sqBOLD methodol... Read More about Model-based Bayesian inference of brain oxygenation using quantitative BOLD.

Simulations of the effect of diffusion on asymmetric spin echo based quantitative BOLD: An investigation of the origin of deoxygenated blood volume overestimation (2019)
Journal Article

Quantitative BOLD (qBOLD) is a technique for mapping oxygen extraction fraction (OEF) and deoxygenated blood volume (DBV) in the human brain. Recent measurements using an asymmetric spin echo (ASE) based qBOLD approach produced estimates of DBV which... Read More about Simulations of the effect of diffusion on asymmetric spin echo based quantitative BOLD: An investigation of the origin of deoxygenated blood volume overestimation.

Prospects for investigating brain oxygenation in acute stroke: experience with a non-contrast quantitative BOLD based approach (2019)
Journal Article

Metabolic markers of baseline brain oxygenation and tissue perfusion have an important role to play in the early identification of ischaemic tissue in acute stroke. Although well established MRI techniques exist for mapping brain perfusion, quantitat... Read More about Prospects for investigating brain oxygenation in acute stroke: experience with a non-contrast quantitative BOLD based approach.

Coupling between cerebral blood flow and cerebral blood volume: contributions of different vascular compartments (2019)
Journal Article

A better understanding of the coupling between changes in cerebral blood flow (CBF) and cerebral blood volume (CBV) is vital for furthering our understanding of the BOLD response. The aim of this study was to measure CBF-CBV coupling in different vas... Read More about Coupling between cerebral blood flow and cerebral blood volume: contributions of different vascular compartments.

Multiparametric measurement of cerebral physiology using calibrated fMRI (2017)
Journal Article

The ultimate goal of calibrated fMRI is the quantitative imaging of oxygen metabolism (CMRO2), and this has been the focus of numerous methods and approaches. However, one underappreciated aspect of this quest is that in the drive to measure CMRO2, m... Read More about Multiparametric measurement of cerebral physiology using calibrated fMRI.

Gas-free calibrated fMRI with a correction for vessel-size sensitivity (2017)
Journal Article

Calibrated functional magnetic resonance imaging (fMRI) is a method to independently measure the metabolic and hemodynamic contributions to the blood oxygenation level dependent (BOLD) signal. This technique typically requires the use of a respirator... Read More about Gas-free calibrated fMRI with a correction for vessel-size sensitivity.

The relationship between blood flow impairment and oxygen depletion in acute ischemic stroke imaged with magnetic resonance imaging (2017)
Journal Article

Rapid cerebrovascular reactivity mapping: Enabling vascular reactivity information to be routinely acquired (2017)
Journal Article

Cerebrovascular reactivity mapping (CVR), using magnetic resonance imaging (MRI) and carbon dioxide as a stimulus, provides useful information on how cerebral blood vessels react under stress. This information has proven to be useful in the study of... Read More about Rapid cerebrovascular reactivity mapping: Enabling vascular reactivity information to be routinely acquired.

A streamlined acquisition for mapping baseline brain oxygenation using quantitative BOLD (2016)
Journal Article

Improving the specificity of R2′ to the deoxyhaemoglobin content of brain tissue: Prospective correction of macroscopic magnetic field gradients (2016)
Journal Article

The reversible transverse relaxation rate, R2′, is sensitive to the deoxyhaemoglobin content of brain tissue, enabling information about the oxygen extraction fraction to be obtained. However, R2′ is also sensitive to macroscopic magnetic field gradi... Read More about Improving the specificity of R2′ to the deoxyhaemoglobin content of brain tissue: Prospective correction of macroscopic magnetic field gradients.

Measurement of oxygen extraction fraction (OEF): An optimized BOLD signal model for use with hypercapnic and hyperoxic calibration (2016)
Journal Article

© 2016 The Authors. Several techniques have been proposed to estimate relative changes in cerebral metabolic rate of oxygen consumption (CMRO2) by exploiting combined BOLD fMRI and cerebral blood flow data in conjunction with hypercapnic or hyperoxic... Read More about Measurement of oxygen extraction fraction (OEF): An optimized BOLD signal model for use with hypercapnic and hyperoxic calibration.

A novel Bayesian approach to accounting for uncertainty in fMRI-derived estimates of cerebral oxygen metabolism fluctuations (2016)
Journal Article

Calibrated blood oxygenation level dependent (BOLD) imaging is a multimodal functional MRI technique designed to estimate changes in cerebral oxygen metabolism from measured changes in cerebral blood flow and the BOLD signal. This technique addresses... Read More about A novel Bayesian approach to accounting for uncertainty in fMRI-derived estimates of cerebral oxygen metabolism fluctuations.

Sources of systematic error in calibrated BOLD based mapping of baseline oxygen extraction fraction (2015)
Journal Article

Hemispheric asymmetry in cerebrovascular reactivity of the human primary motor cortex: an in vivo study at 7 T (2015)
Journal Article

Current functional MRI (fMRI) approaches assess underlying neuronal activity through monitoring the related local variations in cerebral blood oxygenation, blood volume and blood flow. This vascular response is likely to vary across brain regions and... Read More about Hemispheric asymmetry in cerebrovascular reactivity of the human primary motor cortex: an in vivo study at 7 T.

Investigating the field-dependence of the Davis model: Calibrated fMRI at 1.5, 3 and 7 T (2015)
Journal Article

Gas calibrated fMRI in its most common form uses hypercapnia in conjunction with the Davis model to quantify relative changes in the cerebral rate of oxygen consumption (CMRO2) in response to a functional stimulus. It is most commonly carried out at... Read More about Investigating the field-dependence of the Davis model: Calibrated fMRI at 1.5, 3 and 7 T.

Identifying the ischaemic penumbra using pH-weighted magnetic resonance imaging (2014)
Journal Article

© 2014 The Author. The original concept of the ischaemic penumbra suggested imaging of regional cerebral blood flow and metabolism would be required to identify tissue that may benefit from intervention. Amide proton transfer magnetic resonance imagi... Read More about Identifying the ischaemic penumbra using pH-weighted magnetic resonance imaging.