Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 59 for “"Fractional anisotropy"”.
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Delay and probability discounting: a longitudinal study of neural, cognitive, and emotional processes contributing to adolescent development.
… tensor imaging (DTI) measures including fractional anisotropy and mean diffusivity. Delay discounting, but not probability discounting, showed significant maturation within individuals. Greater than expected maturation in delay discounting was seen in individuals with lower internalizing …
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The influence of aerobic fitness on cerebral white matter integrity and cognitive function in older adults: results of a one-year exercise intervention
… adults, we examined longitudinal differences in fractional anisotropy, radial diffusivity and axial diffusivity within the prefrontal, parietal, occipital and temporal lobes. Our results indicate that improved cardiovascular fitness is associated with superior white matter integrity particularly …
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Differences in brain architecture during long-term recovery following mild traumatic brain injury
… and structure (volume, thickness, and fractional anisotropy) in two groups of mTBI – those with 1-10 yrs. time-post injury (mTBI1-10), and those with 20-65 yrs. time post-injury (mTBI20-65), relative to age-, sex-, and education-matched controls. We observed abnormalities in brain …
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The relationship between neurocognitive disorders, prospective memory impairment and white matter damage in clade C HIV-positive subjects
… tensor imaging. We expect that values of fractional anisotropy (FA) - a measure of directional water diffusion- in the frontal white matter will be significantly lower among HIV patients compared to controls 2. Lower FA measured in the frontal white matter will correlate significantly with …
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Associations of serum zinc and copper concentrations within cardiovascular and neurological traits
… matter volume, white matter lesions and global fractional anisotropy. 595 individuals diagnosed with MDD had significantly lower serum zinc and higher serum copper concentrations than 445 community-dwelling controls. In controls, higher serum zinc levels were directly and linearly associated …
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Implementation of anatomical navigators for real time motion correction in diffusion tensor imaging
… and the mean and whole brain histogram of the fractional anisotropy and mean diffusivity were analyzed.
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Investigating white matter alterations and secondary neurodegeneration with MRI imaging and pathology in a mouse model of ischaemic stroke
… (DTI) assessed white matter integrity via fractional anisotropy (FA) and mean diffusivity (MD). Immunohistochemistry evaluated astrocyte (GFAP) and microglia (Iba1) reactivity, axonal damage (APP), myelin integrity (MAG), and secondary neurodegeneration (NeuN). Diffusion tensor imaging …
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The Effects of Daytime Melatonin Administration on Sleep, Higher Cognitive Function, and Changes in the Brain
… negatively affected by the melatonin treatment. Fractional anisotropy and mean diffusivity values were also significantly altered in the inferior frontal gyrus. It is inferred that the melatonin treatment induced circadian desynchronization, resulting in behavioural changes and structural …
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Noise and error propagation in diffusion tensor imaging
… of white matter fiber tracts by measuring the anisotropy of water molecule diffusion in the brain tissue. DTI has been increasingly used in clinical imaging. Diffusion weighted images are affected by noise from the human subject and the MRI scanner. This thesis studies the error propagation in …
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Resting State Functional Magnetic Resonance and Diffusion Tensor Imaging of Hemiplegic Cerebral Palsy Patients Treated with Constraint-Induced Movement Therapy: Predictors and Clinically Correlated Evidence of Neuroplasticity
… patterns and significantly different fractional anisotropy and mean diffusivity in the affected corticospinal tract. Asymmetric baseline sensorimotor network organization was predictive of a positive and continuous functional response to CIMT. Clinically correlated network …
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Diffusion Tensor Imaging and Cognition of Transient Ischemic Attack Patients and Healthy Controls
… fornix, a tract crucial for memory, and lower fractional anisotropy (FA) overall when compared to healthy controls. TIA patients also performed poorer on tests of executive function, episodic and working memory, and processing speed. DTI parameters of FA and MD predicted performance in tests of …
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Biomechanics of Cranial Decompression Procedures in Traumatic Brain Injury
… evaluate differences in white matter integrity (fractional anisotropy, FA) at the regions of strain concentration observed in strain modelling and mirror regions on the contralateral to craniectomy (control) hemisphere. A linear mixed effects model was performed for both anterior and posterior …
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Using open-source data repository initiatives to investigate impaired white matter connectivity in autism
… with ASD showed significantly decreased fractional anisotropy (FA), increased mean diffusivity (MD) and increased radial diffusivity (RD). These results were evident across the entire brain. We did not find any significant relationships between diffusion measures and ADOS or SRS scores. …
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The structural neurobiology of social anxiety disorder : a clinical neuroimaging study
… FSL's tract - based spatial statistics comparing fractional anisotropy (FA), mean diffusivity (MD) in individuals with SAD. Manual tracing demonstrated that compared to controls, SAD patients showed an enlarged right globus pallidus. Cortical thickness analyses demonstrated significant cortical …
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A systematic review of DTI studies in Bipolar Disorder
… using DTI, in adults, and reporting at least fractional anisotropy (FA). Subject, scan and analysis characteristics are extracted. Details of affected tracts are collated, as is the y-axis (anterior/posterior) of the most affected ('peak') voxels.
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Neuroimaging investigation of the motor control disorder, dystonia with special emphasis on laryngeal dystonia
… of the basal ganglia (BG) in dystonia patients. Fractional anisotropy (FA) and probabilistic diffusion tractography analyses were used to investigate the questions of whether LD patients exhibited altered connectivity between BG and brainstem regions and whether FA and tractography could be used …
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Alternative Neuropsychological and Magnetic Resonance Imaging Measures in Multiple Sclerosis: Exploring the relation between brain lesion measured by diffusion tensor magnetic resonance imaging and interhemispheric communication and processing speed in multiple sclerosis
… results in changed diffusion derived measures. Fractional anisotropy is an important diffusion derived measure for inter- and intravoxel fiber coherence. Previous research shows that fractional anisotropy is decreased in MS patients compared to healthy controls. To calculate the fractional …
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Relationship between white matter changes and aggression in methamphetamine dependence
… based spatial statistics (TBSS) in FSL was used. Fractional anisotropy (FA), mean diffusivity (MD), parallel diffusivity (λ║) and perpendicular diffusivity (λ┴) were compared between the two groups. Second, a region of interest (ROI) approach was used, which focused on three WM tracts in the …
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Automated Quality Assurance for Magnetic Resonance Imaging with Extensions to Diffusion Tensor Imaging
… used most in diagnosis, namely, diffusion anisotropy and the direction of primary diffusion. To this end, a physical phantom was constructed to model restricted diffusion, relative to axon size, using water-filled polytetrafluoroethylene (PTFE) microbore capillary tubes. Automated …
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Normalization of Cerebral Blood Flow, Neurochemicals, and White Matter Integrity After Kidney Transplantation
… imaging, and white matter integrity measured by fractional anisotropy (FA) and mean diffusivity (MD) with diffusion tensor imaging. We used a linear mixed model analysis to compare longitudinal, repeated brain MRI measurements pre-KT, and 3 months and 12 months post-KT, and also compared findings …
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