Kevin J. Ray
University of Oxford
Imaging phantomCorrelationPhysicsInternal medicinePerfusion scanningPathologyMagnetic resonance imagingOncologyPerfusionAerospace engineeringCerebral blood flowBlood flowNeuroscienceSpace environmentChemistrySatelliteOrbit (dynamics)Metric (mathematics)In vivoEx vivoProstateSpacecraft chargingHuman brainCharge controlBrain metastasisGliomaBlood–brain barrierTumor hypoxiaProstate cancerMultiple sclerosisShock (circulatory)Magnetization transferPyruvate transportChemical Exchange Saturation Transfer MRIPainful Bladder SyndromeHypofractionated RadiotherapyDose HypofractionationSpacecraftBrain tissueNuclear medicineFunctional studiesAmide protonRisks and benefitsSpin labellingSaturation transferChemical exchangeBootstrap analysisMetastatic breastClin oncolRat brainRat modelMetastasis modelNon invasiveProtein concentrationHealthy volunteersPhantom dataCest mriIschemic strokeEnvironmental scienceNuclear magnetic resonanceRadiation therapyStrokeBreast cancerClinical trialPearson product-moment correlation coefficientSpacecraft designMetabolismRemote sensingEffective diffusion coefficientText miningMedicineSpace technologyBovine serum albumin
13Publications
6H-index
108Citations
Publications 13
Newest
#1Lee Sze Foo (UTAR: Universiti Tunku Abdul Rahman)H-Index: 2
#2James R. Larkin (Medical Research Council)H-Index: 15
Last. Yee Kai Tee (UTAR: Universiti Tunku Abdul Rahman)H-Index: 7
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PURPOSE To assess the correlation and differences between common amide proton transfer (APT) quantification methods in the diagnosis of ischemic stroke. METHODS Five APT quantification methods, including asymmetry analysis and its variants as well as two Lorentzian model-based methods, were applied to data acquired from six rats that underwent middle cerebral artery occlusion scanned at 9.4T. Diffusion and perfusion-weighted images, and water relaxation time maps were also acquired to study the ...
1 CitationsSource
#1Alex K. Smith (University of Oxford)H-Index: 8
#2Kevin J. Ray (University of Oxford)H-Index: 6
Last. Michael A. Chappell (University of Oxford)H-Index: 26
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PURPOSE: Chemical exchange saturation transfer (CEST) is an MRI technique sensitive to the presence of low-concentration solute protons exchanging with water. However, magnetization transfer (MT) effects also arise when large semisolid molecules interact with water, which biases CEST parameter estimates if quantitative models do not account for macromolecular effects. This study establishes under what conditions this bias is significant and demonstrates how using an appropriate model provides mo...
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#1James R. Larkin (Medical Research Council)H-Index: 15
#2Manon A. Simard (Medical Research Council)H-Index: 4
Last. Nicola R. Sibson (Medical Research Council)H-Index: 46
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Cerebral blood flow is an important parameter in many diseases and functional studies that can be accurately measured in humans using arterial spin labelling (ASL) MRI. However, although rat models are frequently used for preclinical studies of both human disease and brain function, rat CBF measurements show poor consistency between studies. This lack of reproducibility is due, partly, to the smaller size and differing head geometry of rats compared to humans, as well as the differing analysis m...
10 CitationsSource
#1Kevin J. Ray (University of Oxford)H-Index: 6
#2Manon A. Simard (Medical Research Council)H-Index: 4
Last. Nicola R. Sibson (Medical Research Council)H-Index: 46
view all 9 authors...
Abnormal pH is a common feature of malignant tumors and has been associated clinically with suboptimal outcomes. Amide proton transfer magnetic resonance imaging (APT MRI) holds promise as a means to noninvasively measure tumor pH, yet multiple factors collectively make quantification of tumor pH from APT MRI data challenging. The purpose of this study was to improve our understanding of the biophysical sources of altered APT MRI signals in tumors. Combining in vivo APT MRI measurements with ex ...
28 CitationsSource
#1Jack J. Miller (University of Oxford)H-Index: 15
#2James T. Grist (University of Cambridge)H-Index: 10
Last. Nicola R. Sibson (Medical Research Council)H-Index: 46
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Hyperpolarised MRI with Dynamic Nuclear Polarisation overcomes the fundamental thermodynamic limitations of conventional magnetic resonance, and is translating to human studies with several early-phase clinical trials in progress including early reports that demonstrate the utility of the technique to observe lactate production in human brain cancer patients. Owing to the fundamental coupling of metabolism and tissue function, metabolic neuroimaging with hyperpolarised [1-13C]pyruvate has the po...
31 CitationsSource
#1Manon A. SimardH-Index: 4
#2James R. LarkinH-Index: 15
Last. Nicola R. SibsonH-Index: 46
view all 8 authors...
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#1Manon A. SimardH-Index: 4
#2James R. LarkinH-Index: 15
Last. Nicola R. SibsonH-Index: 46
view all 8 authors...
Brain perfusion imaging can contribute valuable information in diseases such as cancer and stroke. Arterial spin labelling (ASL) is a non-invasive MRI technique enabling quantification of perfusion by imaging tissue following exchanges of water with magnetically tagged blood. Although ASL has recently been standardised in the clinic1, pre-clinical usage of ASL remains inconsistent between studies. Our aim here was to identify optimal parameters for pre-clinical ASL, taking into account the anato...
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#1Kevin J. Ray (Medical Research Council)H-Index: 6
#2James R. Larkin (Medical Research Council)H-Index: 15
Last. Nicola R. Sibson (Medical Research Council)H-Index: 46
view all 9 authors...
The purpose of this study was to develop realistic phantom models of the intracellular environment of metastatic breast tumour and naive brain, and using these models determine an analysis metric for quantification of CEST MRI data that is sensitive to only labile proton exchange rate and concentration. The ability of the optimal metric to quantify pH differences in the phantoms was also evaluated. Novel phantom models were produced, by adding perchloric acid extracts of either metastatic mouse ...
8 CitationsSource
#1Kevin J. Ray (Medical Research Council)H-Index: 6
#2Nicola R. Sibson (Medical Research Council)H-Index: 46
Last. Anne E. Kiltie (Medical Research Council)H-Index: 36
view all 3 authors...
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