A5008209004- Advanced Neuroimaging Techniques and Applications
- Advanced MRI Techniques and Applications
- Functional Brain Connectivity Studies
- MRI in cancer diagnosis
- Bone and Joint Diseases
- Fetal and Pediatric Neurological Disorders
- NMR spectroscopy and applications
- Genetic Neurodegenerative Diseases
- Neurological disorders and treatments
- Musculoskeletal pain and rehabilitation
- Neural dynamics and brain function
- Tensor decomposition and applications
- Health, Environment, Cognitive Aging
- Neonatal and fetal brain pathology
- Mitochondrial Function and Pathology
- Multiple Sclerosis Research Studies
- Autism Spectrum Disorder Research
- Stroke Rehabilitation and Recovery
- Radiomics and Machine Learning in Medical Imaging
- Amyotrophic Lateral Sclerosis Research
- Pain Management and Opioid Use
- Neurogenesis and neuroplasticity mechanisms
- Congenital heart defects research
- Traumatic Brain Injury Research
- Botulinum Toxin and Related Neurological Disorders
Cardiff University
2016-2025
University Medical Center Utrecht
2012-2024
Australian Catholic University
2017-2023
Health and Care Research Wales
2012-2022
Longwood University
2021
University of Amsterdam
2020
Imagerie et Cerveau
2014-2018
University of Edinburgh
2017
Mental Health Research Institute
2015-2016
King's College London
2000-2016
Abstract Early anatomically based models of language consisted an arcuate tract connecting Broca's speech and Wernicke's comprehension centers; a lesion the resulted in conduction aphasia. However, heterogeneous clinical presentations aphasia suggest greater complexity perisylvian anatomical connections than allowed for classical model. This article re‐explores connectivity using vivo diffusion tensor magnetic resonance imaging tractography. Diffusion data from 11 right‐handed healthy male...
The optimization of acquisition parameters for precise measurement diffusion in anisotropic systems is described. First, an algorithm presented that minimizes the bias inherent making measurements with a fixed set gradient vector directions by spreading out 3-dimensional space. Next, it shown how b—matrices and echo time can be optimized estimating tensor its scalar invariants. standard deviation estimate trace water phantom was reduced more than 40% artefactual anisotropy 60% when using...
To estimate diffusion tensor MRI (DTI) measures, such as fractional anisotropy and fiber orientation, reliably, a large number of diffusion-encoded images is needed, preferably cardiac gated to reduce pulsation artifacts. However, the concomitant longer acquisition times increase chances subject motion adversely affecting estimation these measures. While correcting for artifacts improves accuracy DTI, an often overlooked step in realigning reorient B-matrix so that orientational information...
It has long been recognized that the diffusion tensor model is inappropriate to characterize complex fiber architecture, causing tensor‐derived measures such as primary eigenvector and fractional anisotropy be unreliable or misleading in these regions. There however still debate about impact of this problem practice. A recent study using a Bayesian automatic relevance detection (ARD) multicompartment suggested third white matter (WM) voxels contain crossing fibers, value that, whilst already...
<h3>Aim</h3> To evaluate the association between serum levels of complement component (C) 3, C4 and C1q visual field (VF) loss in patients with primary angle closure glaucoma (PACG). <h3>Methods</h3> In this prospective cohort study, a total 308 PACG were included. The followed up every 6 months (at least 2 years), clinical examination VF testing. Based on their sex age, subjects stratified into male female subgroups, by age at <60 ≥60 years per subgroup. <h3>Results</h3> One hundred...
Abstract There are conflicting opinions in the literature as to whether it is more beneficial use a large number of gradient sampling orientations diffusion tensor MRI (DT‐MRI) experiments than smaller carefully chosen orientations. In this study, Monte Carlo simulations were used study effect using different schemes on estimates tensor‐derived quantities assuming b ‐value 1000 smm –2 . The focused particular that unique has uncertainty tensor‐orientation, and trace anisotropy tensor....
Lateralization of language to the left hemisphere is considered a key aspect human brain organization. We used diffusion tensor MRI perform in vivo virtual dissection pathways assess relationship between asymmetry and cognitive performance normal population. Our findings suggest interhemispheric differences direct connections Broca's Wernicke's territories, with extreme leftward lateralization more than half subjects bilateral symmetrical distribution only 17.5% subjects. Importantly,...
Signal variability in diffusion weighted imaging (DWI) is influenced by both thermal noise and spatially temporally varying artifacts such as subject motion cardiac pulsation. In this paper, the effects of DWI on estimated tensor values, trace fractional anisotropy, are analyzed using Monte Carlo simulations. A novel approach for robust estimation, called RESTORE (for estimation tensors outlier rejection), proposed. This method uses iteratively reweighted least-squares regression to identify...
New diffusion-weighted imaging (DWI) methods, including high-b, q-space, and high angular resolution MRI attempt to extract information about non-Gaussian diffusion in tissue that is not provided by low-b-value (b approximately 1000 s mm(-2)) or tensor magnetic resonance (DT-MRI). Additionally, DWI data with higher spatial are being acquired resolve fine anatomic structures, such as white matter fasciculi. Increasing diffusion-weighting decreasing voxel size can reduce the signal-to-noise...
Functional imaging of the human brain is an increasingly important technique for clinical and cognitive neuroscience research, with functional MRI (fMRI) blood oxygen level-dependent (BOLD) response electroencephalography or magnetoencephalography (MEG) recordings neural oscillations being 2 most popular approaches. However, physiological mechanisms that generate these responses are only partially understood sources interparticipant variability in measures rarely investigated. Here, we test...
A technique for assessing in vivo fiber connectivity the human brain is presented. The method utilizes a novel algorithm that operates three spatial dimensions and uses estimates of tract orientation tissue anisotropy, obtained from diffusion tensor magnetic resonance imaging, to establish pathways tracts. Sample images healthy are presented demonstrate connections white matter White information potentially interest study range neurological, psychiatric, developmental disorders shows promise...
Abstract The driven‐equilibrium single‐pulse observation of T 1 (DESPOT1) and 2 (DESPOT2) are rapid, accurate, precise methods for voxelwise determination the longitudinal transverse relaxation times. A limitation methods, however, is inherent assumption single‐component relaxation. In a variety biological tissues, in particular human white matter (WM) gray (GM), has been shown to be more completely characterized by summation two or components, species, each believed associated with unique...
<b><i>Background:</i></b> A number of neurophysiologic and neuroimaging techniques have been evaluated in the research setting to assess upper motor neuron (UMN) damage ALS. Changes tissue structure CNS modify diffusional behavior water molecules, which can be detected by diffusion tensor MRI. <b><i>Objectives:</i></b> To explore hypothesis that degeneration fibers ALS would reflected changes characteristics white matter posterior limb internal capsule these could <b><i>Methods:</i></b> We...
Constrained spherical deconvolution (CSD) is a new technique that, based on high-angular resolution diffusion imaging (HARDI) MR data, estimates the orientation of multiple intravoxel fiber populations within regions complex white matter architecture, thereby overcoming limitations widely used tensor (DTI) technique. One its main applications tractography. The noisy nature diffusion-weighted (DW) images, however, affects estimated orientations and resulting trajectories will be subject to...