Anisotrophy

Widespread expression of leptin and its receptor in developing cartilage and bone suggests that leptin may regulate bone growth and development in the fetus. Using micro-computed tomography, this study investigated the effects of exogenous leptin and leptin receptor antagonism on aspects of bone structure in the sheep fetus during late gestation. From 125-130 days of gestation (term ~145 days), chronically-catheterised singleton sheep fetuses were infused intravenously for five days with either saline (0.9% saline, n=13), recombinant ovine leptin at two doses (0...

Transient hypothyroidism is common in premature infants and increases the risk of adverse neurodevelopmental outcomes. Thyroid hormone (TH) is involved in oligodendrocyte development and myelination, however, whether transient hypothyroidism is associated with oligodendrocyte dysplasia and abnormal myelination is unclear. The aim of the present study was to investigate correlations among TH levels, neurodevelopmental outcomes and white matter (WM) microstructure in premature infants. The authors designed a cohort study recruiting 81 premature infants (age, 23-35 weeks)...

We present a method to discover differences between populations with respect to the spatial coherence of their oriented white matter microstructure in arbitrarily shaped white matter regions. This method is applied to diffusion MRI scans of a subset of the Human Connectome Project dataset: 57 pairs of monozygotic and 52 pairs of dizygotic twins. After controlling for morphological similarity between twins, we identify 3.7% of all white matter as being associated with genetic similarity (35.1 k voxels, p<10-4, false discovery rate 1...

BACKGROUND: Type 2 Diabetes (T2D) is associated with increased risk of dementia. We aimed to determine the feasibility of a randomised controlled trial (RCT) examining the efficacy of exercise on cognition and brain structure in people with T2D. METHODS: A 6-month pilot parallel RCT of a progressive aerobic- and resistance-training program versus a gentle movement control group in people with T2D aged 50-75 years (n = 50) at the University of Tasmania, Australia...

Combining structural and functional magnetic resonance imaging may provide insight into how residual motor networks contribute to motor outcomes post-stroke. The purpose of this study was to examine whether a structural motor network (SMN), generated with fMRI guided diffusion-based tractography, relates to motor function post-stroke. Twenty-seven individuals with mild to moderate upper limb impairment post stroke underwent diffusion magnetic resonance imaging. A bilateral motor network mask guided white matter tractography for each participant...

OBJECTIVE: Metabolic complications are frequent in childhood leukaemia (ALL) survivors treated with cranial radiotherapy (CRT). These complications are potentially mediated by damage to the hypothalamus (HT), as childhood onset (CO) craniopharyngioma (CP) survivors without HT involvement are spared overt obesity. Diffusion tensor imaging (DTI) shows brain tissue microstructure alterations, by fractional anisotrophy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD)...

INTRODUCTION: To explore the neuroanatomical correlates of primary writing tremor (PWT) and the role of cerebellum, using advanced structural neuroimaging. Till date, there are no studies exploring the gray and white matter changes using voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) in PWT. METHODS: Ten male patients with PWT were evaluated clinically and with magnetic resonance imaging. VBM and DTI images of patients were compared with that of 10 healthy male subjects...

Diffusion tensor imaging (DTI) is an increasingly used noninvasive imaging tool. However its long-term clinical utility is unclear. Parkinson's disease (PD) is a common neurodegenerative disease.We prospectively examined a cohort of 46 Parkinson's disease (PD) patients who underwent diffusion tensor imaging (DTI) of the brain at baseline and 6 years later on a 1.5 Tesla scanner using a standardized protocol. DTI parameters of mean diffusivity (MD) and fractional anisotrophy (FA) were extracted using regions-of-interest (ROIs) analysis from various brain regions...

Although research on the effects of mindfulness meditation (MM) is increasing, still very little has been done to address its influence on the white matter (WM) of the brain. We hypothesized that the practice of MM might affect the WM microstructure adjacent to five brain regions of interest associated with mindfulness. Diffusion tensor imaging was employed on samples of meditators and non-meditators (n = 64) in order to investigate the effects of MM on group difference and aging. Tract-Based Spatial Statistics was used to estimate the fractional anisotrophy of the WM connected to the thalamus, insula, amygdala, hippocampus, and anterior cingulate cortex...

PURPOSE: To evaluate the effectiveness of Riluzole as a pharmacotherapeutic treatment option for early cervical myelopathy using clinical parameters and DTI analysis. METHODS: Early cervical myelopathy cases with MJOA scores ≥13, were recruited for the double-blinded, placebo-controlled randomised control trial. Thirty cases with fifteen cases each in the test and placebo group were studied. Analysis was done using diffusion tensor imaging (DTI) and clinical evaluation, pre- and post-institution of sodium channel blocker Riluzole for a period of 1 month (50 mg twice daily)...

Although motor neuron degeneration is the predominant feature in ALS, recent data point to a more widespread pathology also comprising non-motor symptoms. Retinal thinning has been reported in a variety of neurodegenerative conditions. Yet, studies of retinal involvement in ALS are sparse and results are heterogeneous. We studied retinal alterations in ALS using a systematic approach combining Optical Coherence Tomography (OCT), Diffusion Tensor Imaging (DTI) and clinical phenotyping. We hypothesized that selective changes of specific retinal layers may be a reflection of overall neurodegeneration as measured by DTI...

BACKGROUND: Previous morphology and diffusion-imaging studies have suggested that structural changes in white matter is an important part of the pathophysiology of obsessive-compulsive disorder (OCD). However, different methodological approaches and the heterogeneity of patient samples question the validity of the findings. Materials and methods In total, 30 patients were matched for age and sex with 30 healthy controls. All participants underwent T1-weighted magnetic resonance imaging, diffusion tensor imaging and T2 fluid-attenuated inversion recovery...

Previous studies have demonstrated that Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) exhibited anatomical and functional abnormalities in the anterior cingulate cortex (ACC) and accumulating evidence supported the hypothesis that changes in the ACC predict the progression from aMCI to AD. In this study, we aimed to explore how the two functional and structural heterogeneous sub-regions of ACC, namely the dorsal ACC (dACC) and the ventral ACC (vACC), changed in aMCI and whether the structural connectivity affects the functional connectivity between the two ACC subregions...

Segmentation and parcellation of the thalamus is an important step in providing volumetric assessment of the impact of disease n brain structures. Conventionally, segmentation is carried out on T1-weighted magnetic resonance (MR) images and nuclear parcellation using diffusion weighted MR images. We present the first fully automatic method that incorporates both tissue contrasts and several derived fea-fractional anisotrophy, fiber orientation from the 5D Knutsson representation of the principal eigenvectors, and connectivity between the thalamus and the cortical lobes, as features...

Unilateral condylar hyperplasia or hyperactivity is a disorder of growth that affects the mandible, and our aim was to visualise the 3-dimensional bony microstructure of resected mandibular condyles of affected patients. We prospectively studied 17 patients with a clinical presentation of progressive mandibular asymmetry and an abnormal single-photon emission computed tomographic (SPECT) scan. All patients were treated by condylectomy to arrest progression. The resected condyles were scanned with micro-CT (18 μm resolution)...

BACKGROUND: No study on the characteristics of injury of the corticospinal tract (CST) or corticoreticular pathway (CRP) in patients with putaminal hemorrhage has been reported. In this study, using diffusion tensor tractography, we attempted to investigate the characteristics of injury of the CST and CRP in hemiparetic patients with putaminal hemorrhage. METHOD: Fifty seven consecutive patients with putaminal hemorrhage and 57 healthy control subjects were recruited for this study...

Epilepsy is more than a grey-matter disorder affecting large white matter connections of the brain with seizure generation and propagation. The mechanism for such changes remains unclear. The purpose of this study was to investigate the microstructural changes in the corpus callosum in temporal lobe epilepsy (TLE) patients and whether these abnormalities are related to antiepileptic drug (AED) therapy. Ten TLE patients receiving AED therapy, ten TLE patients with no therapy and ten controls were included in the study...

The aim of this study was to investigate spinal cord injury (SCI) on the basis of diffusion tensor imaging (DTI) in patients with high-voltage electrical injury. We recruited eight high-voltage electrical injury patients and eight healthy subjects matched for age and sex. DTI and central motor conduction time were acquired in both the patient and control groups. We obtained DTI indices according to the spinal cord levels (from C2 to C7) and cross-section locations (anterior, lateral, and posterior). Fractional anisotrophy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were compared between the two groups; additionally, they were compared in relation to spinal cord level and cross-section location...

PURPOSE: To evaluate the feasibility of diffusion tensor imaging (DTI) for the medial and lateral rectus extraocular muscle (EOM) evaluation, to investigate the normal DTI parameters of the medial and lateral rectus EOM, and to compare with other skeletal muscle. MATERIALS AND METHODS: Seven multiple sclerosis patients and five normal subjects (M:F = 5:7, mean age = 31.6 ± 9.2) without EOM disorder were included. The orbital DTIs using 2D-ss-IMVI-DWEPI were scanned with b = 500 s/mm(2) and 12 directions...

BACKGROUND CONTEXT: Signal intensity changes observed in magnetic resonance imaging (MRI) do not reveal the actual severity of axonal damage incurred in spinal cord injuries. Diffusion tensor imaging (DTI) is an imaging technique with a potential to track individual nerve fiber tracts. PURPOSE: We explored the use of DTI in quantifying the extent of spinal cord injury and differentiated areas of injured spinal cord from regions with intact fiber tracts in a cadaveric animal model...