5 results on '"Steven C.R. Williams"'
Search Results
2. Silent myelin-weighted magnetic resonance imaging [version 2; peer review: 2 approved, 2 approved with reservations]
- Author
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Tobias C. Wood, Nikou L. Damestani, Andrew J. Lawrence, Emil Ljungberg, Gareth J. Barker, Ana Beatriz Solana, Florian Wiesinger, and Steven C.R. Williams
- Subjects
lcsh:R ,lcsh:Medicine ,lcsh:Q ,lcsh:Science - Abstract
Background: Inhomogeneous Magnetization Transfer (ihMT) is an emerging, uniquely myelin-specific magnetic resonance imaging (MRI) contrast. Current ihMT acquisitions utilise fast Gradient Echo sequences which are among the most acoustically noisy MRI sequences, reducing patient comfort during acquisition. We sought to address this by modifying a near silent MRI sequence to include ihMT contrast. Methods: A Magnetization Transfer preparation module was incorporated into a radial Zero Echo-Time sequence. Repeatability of the ihMT ratio and inverse ihMT ratio were assessed in a cohort of healthy subjects. We also investigated how head orientation affects ihMT across subjects, as a previous study in a single subject suggests this as a potential confound. Results: We demonstrated that ihMT ratios comparable to existing, acoustically loud, implementations could be obtained with the silent sequence. We observed a small but significant effect of head orientation on inverse ihMTR. Conclusions: Silent ihMT imaging is a comparable alternative to conventional, noisy, alternatives. For all future ihMT studies we recommend careful positioning of the subject within the scanner.
- Published
- 2020
3. Silent myelin-weighted magnetic resonance imaging
- Author
-
Tobias C. Wood, Nikou L. Damestani, Andrew J. Lawrence, Emil Ljungberg, Gareth J. Barker, Ana Beatriz Solana, Florian Wiesinger, and Steven C.R. Williams
- Subjects
03 medical and health sciences ,0302 clinical medicine ,Medicine (miscellaneous) ,psychological phenomena and processes ,030217 neurology & neurosurgery ,General Biochemistry, Genetics and Molecular Biology ,030218 nuclear medicine & medical imaging - Abstract
Background: Inhomogeneous Magnetization Transfer (ihMT) is an emerging, uniquely myelin-specific magnetic resonance imaging (MRI) contrast. Current ihMT acquisitions utilise fast Gradient Echo sequences which are among the most acoustically noisy MRI sequences, reducing patient comfort during acquisition. We sought to address this by modifying a near silent MRI sequence to include ihMT contrast. Methods: A Magnetization Transfer preparation module was incorporated into a radial Zero Echo-Time sequence. Repeatability of the ihMT ratio and inverse ihMT ratio were assessed in a cohort of healthy subjects. We also investigated how head orientation affects ihMT across subjects, as a previous study in a single subject suggests this as a potential confound. Results: We demonstrated that ihMT ratios comparable to existing, acoustically loud, implementations could be obtained with the silent sequence. We observed that the ihMT ratio varied with the orientation of the head. Conclusions: Silent ihMT imaging is a comparable alternative to conventional, noisy, alternatives. For all future ihMT studies we recommend careful attention should be paid to subject positioning within the scanner.
- Published
- 2020
4. Workshop proceedings, Jan 25-26th 2017
- Author
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Karen Horsburgh, Joanna M. Wardlaw, Tom van Agtmael, Stuart M. Allan, Mike L.J. Ashford, Philip M. Bath, Rosalind Brown, Jason Berwick, M. Zameel Cader, Roxana O. Carare, John B. Davis, Jessica Duncombe, Tracy D. Farr, Jill H. Fowler, Jozien Goense, Alessandra Granata, Catherine N. Hall, Atticus H. Hainsworth, Adam Harvey, Cheryl A. Hawkes, Anne Joutel, Rajesh N. Kalaria, Patrick G. Kehoe, Catherine B. Lawrence, Andy Lockhart, Seth Love, Malcolm R. Macleod, I. Mhairi Macrae, Hugh S. Markus, Chris McCabe, Barry W. McColl, Paul J. Meakin, Alyson Miller, Maiken Nedergaard, Michael O'Sullivan, Terry J. Quinn, Rikesh Rajani, Lisa M. Saksida, Colin Smith, Kenneth J. Smith, Rhian M. Touyz, Rebecca C. Trueman, Tao Wang, Anna Williams, Steven C.R. Williams, and Lorraine M. Work
- Subjects
0301 basic medicine ,Gerontology ,Lydia Becker Institute ,Scope (project management) ,Vascular disease ,business.industry ,Psychological intervention ,Review ,General Medicine ,Disease ,medicine.disease ,Article ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,ResearchInstitutes_Networks_Beacons/lydia_becker_institute_of_immunology_and_inflammation ,Journal Article ,medicine ,Dementia ,Small vessel ,Cognitive impairment ,business ,Stroke ,030217 neurology & neurosurgery - Abstract
Cerebral small vessel disease (SVD) is a major health challenge. Therapeutic approaches remain limited, hampered by the lack of mechanistic understanding and identification of therapeutic targets. Relevant animal models could provide a cornerstone to basic scientific studies of disease mechanisms and pre-clinical studies of potential therapies, but there is a critical need to improve the current translational gap that exists between pre-clinical research and treatments in patients. The Medical Research Council Dementias Platform UK (MRC DPUK) Vascular Experimental Medicine Theme identified that a comprehensive assessment of the latest developments in animal models and of their contribution to understanding of cerebral microvascular disease would reduce the translational gap. In response to this, a two day workshop took place in late January 2017 at the British Heart Foundation Centre of Research Excellence in Glasgow, Scotland in conjunction with MRC DPUK and brought together experts from several disciplines in cerebrovascular disease, dementia and cardiovascular biology, to highlight current advances in these fields, explore synergies and scope for development. There were presentations from UK and international researchers and a specific focus on animal models of cerebral microvascular disease and dementia, considering vascular biology, neurogliovascular coupling, blood-brain barrier function, neuroinflammation, cerebral drainage pathways, and methodological and translational challenges (see Figure 1 for the general organisation of the meeting including the key topics and themes discussed). This overview provides a summary of the key talks, with a particular focus on mechanisms of cerebral vascular disease (see Figure 2) and improving translation. These talks were followed by related themed discussion groups on the gaps in knowledge and requirements to advance knowledge, the outcomes of which are highlighted in Table 1. Additional related articles are published in the Special Edition of Clinical Science (http://www.portlandpresspublishing.com/cc/small-vessels).
- Published
- 2018
5. A diffusion tensor imaging study of fasciculi in schizophrenia
- Author
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Sukhwinder S. Shergill, Richard A. Kanaan, Xavier A. Chitnis, Owen O’Daly, Derek K. Jones, Sophia Frangou, Steven C.R. Williams, Robert J. Howard, Gareth J. Barker, Robin M. Murray, and Philip McGuire
- Subjects
Adult ,Cerebral Cortex ,Male ,Brain Mapping ,Hallucinations ,BF ,Prefrontal Cortex ,behavioral disciplines and activities ,Severity of Illness Index ,Functional Laterality ,Temporal Lobe ,Corpus Callosum ,Psychiatry and Mental health ,Diffusion Magnetic Resonance Imaging ,Parietal Lobe ,Neural Pathways ,Image Processing, Computer-Assisted ,Schizophrenia ,Anisotropy ,Humans ,Female ,Schizophrenic Psychology - Abstract
Objective: Cognitive models propose that the symptoms and psychological impairments associated with schizophrenia arise as a consequence of impaired communication between brain regions, especially the prefrontal cortex and the temporal and parietal lobes. Functional imaging and electrophysiological data have provided evidence of functional dysconnectivity, but it is unclear whether this reflects an underlying problem with anatomical connectivity. This study used diffusion tensor imaging to examine the integrity of the major white matter fasciculi, which connects the frontal and temporal-parietal cortices, and the corpus callosum in patients with schizophrenia. Method: A 1.5-T magnetic resonance scanner was used to acquire diffusion tensor images giving whole brain coverage at an isotropic 2.5-mm voxel size. Fractional anisotropy was measured in 33 patients with schizophrenia and 40 healthy comparison subjects with an automated voxel-based method of analysis. Results: There was reduced fractional anisotropy in patients with schizophrenia in regions corresponding to the superior longitudinal fasciculi bilaterally and in the genu of the corpus callosum. However, within the patient group, the propensity to experience auditory hallucinations was associated with relatively increased fractional anisotropy in superior longitudinal fasciculi and in the anterior cingulum. Conclusions: Schizophrenia is associated with altered white matter integrity in the tracts connecting the frontal cortex with the temporal and parietal cortices and with the contralateral frontal and temporal lobes. The severity of these changes may vary with the pattern of symptoms associated with the disorder. Abstract Teaser
- Published
- 2007
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