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Improving quantitative BOLD–based measures of oxygen extraction fraction using hyperoxia BOLD–derived measures of blood volume (2025)
Journal Article
Stone, A. J., & Blockley, N. P. (2025). Improving quantitative BOLD–based measures of oxygen extraction fraction using hyperoxia BOLD–derived measures of blood volume. Magnetic Resonance in Medicine, https://doi.org/10.1002/mrm.30559

Purpose: Streamlined quantitative BOLD (sqBOLD) is a refinement of the quantitative BOLD (qBOLD) technique capable of producing noninvasive and quantitative maps of oxygen extraction fraction (OEF) in a clinically feasible scan time. However, sqBOLD... Read More about Improving quantitative BOLD–based measures of oxygen extraction fraction using hyperoxia BOLD–derived measures of blood volume.

Development of Resorbable Phosphate-Based Glass Microspheres as MRI Contrast Media Agents (2024)
Journal Article
Molinar-Díaz, J., Arjuna, A., Abrehart, N., McLellan, A., Harris, R., Islam, M. T., Alzaidi, A., Bradley, C. R., Gidman, C., Prior, M. J., Titman, J., Blockley, N. P., Harvey, P., Marciani, L., & Ahmed, I. (2024). Development of Resorbable Phosphate-Based Glass Microspheres as MRI Contrast Media Agents. Molecules, 29(18), Article 4296. https://doi.org/10.3390/molecules29184296

In this research, resorbable phosphate-based glass (PBG) compositions were developed using varying modifier oxides including iron (Fe2O3), copper (CuO), and manganese (MnO2), and then processed via a rapid single-stage flame spheroidisation process t... Read More about Development of Resorbable Phosphate-Based Glass Microspheres as MRI Contrast Media Agents.

Quantitative BOLD (qBOLD) imaging of oxygen metabolism and blood oxygenation in the human body: A scoping review (2024)
Journal Article
Alzaidi, A. A., Panek, R., & Blockley, N. P. (2024). Quantitative BOLD (qBOLD) imaging of oxygen metabolism and blood oxygenation in the human body: A scoping review. Magnetic Resonance in Medicine, https://doi.org/10.1002/mrm.30165

Purpose
There are many approaches to the quantitative BOLD (qBOLD) technique described in the literature, differing in pulse sequences, MRI parameters and data processing. Thus, in this review, we summarized the acquisition methods, approaches used... Read More about Quantitative BOLD (qBOLD) imaging of oxygen metabolism and blood oxygenation in the human body: A scoping review.

Altered oxidative neurometabolic response to methylene blue in bipolar disorder revealed by quantitative neuroimaging (2024)
Journal Article
Russo, A., Örzsik, B., Yalin, N., Simpson, I., Nwaubani, P., Pinna, A., De Marco, R., Sharp, H., Kartar, A., Singh, N., Blockley, N., Stone, A. J. L., Turkheimer, F. E., Young, A. H., Cercignani, M., Zelaya, F., Asllani, I., & Colasanti, A. (2024). Altered oxidative neurometabolic response to methylene blue in bipolar disorder revealed by quantitative neuroimaging. Journal of Affective Disorders, 362, 790-798. https://doi.org/10.1016/j.jad.2024.07.029

Background: Cerebral mitochondrial and hemodynamic abnormalities have been implicated in Bipolar Disorder pathophysiology, likely contributing to neurometabolic vulnerability–leading to worsen clinical outcomes and mood instability. To investigate ne... Read More about Altered oxidative neurometabolic response to methylene blue in bipolar disorder revealed by quantitative neuroimaging.

Cortical oxygen extraction fraction using quantitative BOLD MRI and cerebral blood flow during vasodilation (2023)
Journal Article
Le, L. N. N., Wheeler, G. J., Holy, E. N., Donnay, C. A., Blockley, N. P., Yee, A. H., Ng, K. L., & Fan, A. P. (2023). Cortical oxygen extraction fraction using quantitative BOLD MRI and cerebral blood flow during vasodilation. Frontiers in Physiology, 14, Article 1231793. https://doi.org/10.3389/fphys.2023.1231793

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
Pinto, J., Blockley, N. P., Harkin, J. W., & Bulte, D. P. (2023). Modelling spatiotemporal dynamics of cerebral blood flow using multiple-timepoint arterial spin labelling MRI. Frontiers in Physiology, 14, Article 1142359. https://doi.org/10.3389/fphys.2023.1142359

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
Msayib, Y., Harston, G. W., Ray, K. J., Larkin, J. R., Sutherland, B. A., Sheerin, F., Blockley, N. P., Okell, T. W., Jezzard, P., Baldwin, A., Sibson, N. R., Kennedy, J., & Chappell, M. A. (2022). Quantitative chemical exchange saturation transfer imaging of nuclear overhauser effects in acute ischemic stroke. Magnetic Resonance in Medicine, 88(1), 341-356. https://doi.org/10.1002/mrm.29187

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
Suri, S., Bulte, D., Chiesa, S. T., Ebmeier, K. P., Jezzard, P., Rieger, S. W., Pitt, J. E., Griffanti, L., Okell, T. W., Craig, M., Chappell, M. A., Blockley, N. P., Kivimäki, M., Singh-Manoux, A., Khir, A. W., Hughes, A. D., Deanfield, J. E., Jensen, D. E. A., Green, S. F., Sigutova, V., …Mackay, C. E. (2021). Study Protocol: The Heart and Brain Study. Frontiers in Physiology, 12, Article 643725. https://doi.org/10.3389/fphys.2021.643725

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
Cherukara, M. T., Stone, A. J., Chappell, M. A., & Blockley, N. P. (2019). Model-based Bayesian inference of brain oxygenation using quantitative BOLD. NeuroImage, 202, Article 116106. https://doi.org/10.1016/j.neuroimage.2019.116106

© 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
Stone, A. J., Holland, N. C., Berman, A. J., & Blockley, N. P. (2019). Simulations of the effect of diffusion on asymmetric spin echo based quantitative BOLD: An investigation of the origin of deoxygenated blood volume overestimation. NeuroImage, 201, Article 116035. https://doi.org/10.1016/j.neuroimage.2019.116035

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
Stone, A. J., Harston, G. W. J., Carone, D., Okell, T. W., Kennedy, J., & Blockley, N. P. (2019). Prospects for investigating brain oxygenation in acute stroke: experience with a non-contrast quantitative BOLD based approach. Human Brain Mapping, 40(10), 2853-2866. https://doi.org/10.1002/hbm.24564

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
Wesolowski, R., Blockley, N., Driver, I., Francis, S., & Gowland, P. (2019). Coupling between cerebral blood flow and cerebral blood volume: contributions of different vascular compartments. NMR in Biomedicine, 32(3), 1-11. https://doi.org/10.1002/nbm.4061

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
Bright, M. G., Croal, P. L., Blockley, N. P., & Bulte, D. P. (2019). Multiparametric measurement of cerebral physiology using calibrated fMRI. NeuroImage, 187, 128-144. https://doi.org/10.1016/j.neuroimage.2017.12.049

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
Berman, A. J., Mazerolle, E. L., MacDonald, M. E., Blockley, N. P., Luh, W.-M., & Pike, G. B. (2018). Gas-free calibrated fMRI with a correction for vessel-size sensitivity. NeuroImage, 169, 176-188. https://doi.org/10.1016/j.neuroimage.2017.12.047

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.

Rapid cerebrovascular reactivity mapping: Enabling vascular reactivity information to be routinely acquired (2017)
Journal Article
Blockley, N. P., Harkin, J. W., & Bulte, D. P. (2017). Rapid cerebrovascular reactivity mapping: Enabling vascular reactivity information to be routinely acquired. NeuroImage, 159, 214-223. https://doi.org/10.1016/j.neuroimage.2017.07.048

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.

Improving the specificity of R2′ to the deoxyhaemoglobin content of brain tissue: Prospective correction of macroscopic magnetic field gradients (2016)
Journal Article
Blockley, N. P., & Stone, A. J. (2016). Improving the specificity of R2′ to the deoxyhaemoglobin content of brain tissue: Prospective correction of macroscopic magnetic field gradients. NeuroImage, 135, 253-260. https://doi.org/10.1016/j.neuroimage.2016.04.013

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
Merola, A., Murphy, K., Stone, A. J., Germuska, M. A., Griffeth, V. E., Blockley, N. P., Buxton, R. B., & Wise, R. G. (2016). Measurement of oxygen extraction fraction (OEF): An optimized BOLD signal model for use with hypercapnic and hyperoxic calibration. NeuroImage, 129, 159-174. https://doi.org/10.1016/j.neuroimage.2016.01.021

© 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
Simon, A. B., Dubowitz, D. J., Blockley, N. P., & Buxton, R. B. (2016). A novel Bayesian approach to accounting for uncertainty in fMRI-derived estimates of cerebral oxygen metabolism fluctuations. NeuroImage, 129, 198-213. https://doi.org/10.1016/j.neuroimage.2016.01.001

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.