scholarly journals Diffusion Tensor Imaging Studies on Chinese Patients with Social Anxiety Disorder

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Changjian Qiu ◽  
Chunyan Zhu ◽  
Jingna Zhang ◽  
Xiaojing Nie ◽  
Yuan Feng ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Anxiety Disorder ◽  
White Matter ◽  
Diffusion Tensor ◽  
Inferior Frontal Gyrus ◽  
Middle Temporal Gyrus ◽  
Left Inferior Frontal Gyrus ◽  
Middle Temporal ◽  
Adc Values ◽  
Left Insula

The aim of this study was to explore white-matter disruption in social anxiety disorder (SAD) patients by using diffusion tensor imaging (DTI) and to investigate the relationship between cerebral abnormalities and the severity of the symptoms. Eighteen SAD patients and age- and gender-matched healthy controls were recruited. DTI scans were performed to measure fractional anisotropy (FA) and apparent diffusion coefficient (ADC) for each subject. We used voxel-based analysis to determine the differences of FA and ADC values between the two groups with two-samplet-tests. The SAD patient showed significantly decreased FA values in the white matter of the left insula, left inferior frontal gyrus, left middle temporal gyrus, and left inferior parietal gyrus and increased ADC values in the left insula, bilateral inferior frontal gyrus, bilateral middle temporal gyrus, and left inferior parietal gyrus. In SAD patients, we observed a significant negative correlation between FA values in the left insula and the total LSAS scores and a positive correlation between the ADC values in the left inferior frontal gyrus and the total LSAS scores. Above results suggested that white-matter microstructural changes might contribute to the neuropathology of SAD.

scholarly journals Diffusion tensor imaging analysis of the brain in the canine model of Krabbe disease

2016 ◽  
Vol 29 (6) ◽  
pp. 417-424 ◽  
Author(s):  
Allison Bradbury ◽  
David Peterson ◽  
Charles Vite ◽  
Steven Chen ◽  
N Matthew Ellinwood ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Mr Imaging ◽  
Gray Matter ◽  
Diffusion Tensor ◽  
Ex Vivo ◽  
Small Animal ◽  
Krabbe Disease ◽  
Adc Values ◽  
The Brain

Purpose The goal of this study was to compare the diffusion tensor imaging (DTI) metrics from an end-stage canine Krabbe brain evaluated by MR imaging ex vivo to those of a normal dog brain. We hypothesized that the white matter of the canine Krabbe brain would show decreased fractional anisotropy (FA) values and increased apparent diffusion coefficient (ADC) and radial diffusivity (RD) values. Methods An 11-week-old Krabbe dog was euthanized after disease progression. The brain was removed and was placed in a solution of 10% formalin. MR imaging was performed and compared to the brain images of a normal dog that was similarly fixed post-mortem. Both brains were scanned using similar protocols on a 7 T small-animal MRI system. For each brain, maps of ADC, FA, and RD were calculated for 11 white-matter regions and five control gray-matter regions. Results Large decreases in FA values, increases in ADC values, and increases in RD (consistent with demyelination) values, were seen in white matter of the Krabbe brain but not gray matter. ADC values in gray matter of the Krabbe brain were decreased by approximately 29% but increased by approximately 3.6% in white matter of the Krabbe brain. FA values in gray matter were decreased by approximately 3.3% but decreased by approximately 29% in white matter. RD values were decreased by approximately 27.2% in gray matter but increased by approximately 20% in white matter. Conclusion We found substantial abnormalities of FA, ADC, and RD values in an ex vivo canine Krabbe brain.

scholarly journals White Matter Abnormalities in Body Integrity Dysphoria

2021 ◽  
Author(s):  
Gianluca Saetta ◽  
Kathy Ruddy ◽  
Laura Zapparoli ◽  
Martina Gandola ◽  
Gerardo Salvato ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Inferior Frontal Gyrus ◽  
Structural Connectivity ◽  
The Body ◽  
Limb Amputation ◽  
Middle Temporal Gyrus ◽  
Imaging Data ◽  
Severe Condition ◽  
The Right

Body integrity dysphoria (BID) is a severe condition affecting non-psychotic individuals where a limb may be experienced as non-belonging, despite normal anatomical development and intact sensorimotor functions. Limb amputation is desired for restoring their own identity. We previously demonstrated altered brain structural (gray matter) and functional connectivity in 16 men with a long-lasting and exclusive desire for left leg amputation. Here we aimed to identify in the same sample altered patterns of white matter structural connectivity. Fractional anisotropy (FA), derived from Diffusion Tensor Imaging data, was considered as a measure of structural connectivity. Results showed reduced structural connectivity of: i) the right superior parietal lobule (rSPL) with the right cuneus, superior occipital and posterior cingulate gyri, and cuneus, ii) the pars orbitalis of the right middle frontal gyrus (rMFGOrb) with the putamen iii) the left middle temporal gyrus (lMTG) with the pars triangularis of the left inferior frontal gyrus. Increased connectivity was observed between the right paracentral lobule (rPLC) and the right caudate nucleus. By using a complementary method of investigation, we confirmed and extended previous results showing alterations in areas tuned to the processing of the sensorimotor representations of the affected leg (rPCL), and to higher-order components of bodily representation such as the body image (rSPL). Alongside this network for bodily awareness, other networks such as the limbic (rMFGOrb) and the mirror (lMTG) systems showed structural alterations as well. These findings consolidate current understanding of the neural correlates of BID, which might in turn guide diagnostics and rehabilitative treatments.

scholarly journals Sensory processing sensitivity and axonal microarchitecture: Identifying brain structural characteristics for behavior

2021 ◽  
Author(s):  
Szabolcs David ◽  
Lucy L Brown ◽  
Anneriet M Heemskerk ◽  
Elaine Aron ◽  
Alexander Leemans ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Sensory Processing ◽  
Diffusion Tensor ◽  
Structural Characteristics ◽  
Inferior Frontal Gyrus ◽  
Mean Diffusivity ◽  
Human Connectome Project ◽  
Sensory Processing Sensitivity ◽  
The Right

Previously, researchers used functional MRI to identify regional brain activations associated with sensory processing sensitivity (SPS), a proposed normal phenotype trait. To further validate SPS as a behavioral entity, to characterize it anatomically, and to test the usefulness in psychology of methodologies that assess axonal properties, the present study correlated SPS proxy questionnaire scores (adjusted for neuroticism) with diffusion tensor imaging measures. Participants (n=408) from the Young Adult Human Connectome Project that are free of neurologic and psychiatric disorders were investigated. We computed mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD) and fractional anisotropy (FA). A voxelwise, exploratory analysis showed that MD and RD correlated positively with SPS proxy scores in the right and left subcallosal and anterior ventral cingulum bundle, and the right forceps minor of the corpus callosum (peak Cohens D effect size = 0.269). Further analyses showed correlations throughout the entire right and left ventromedial prefrontal cortex, including the superior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate and arcuate fasciculus. These prefrontal regions are generally involved in emotion, reward and social processing. FA was negatively correlated with SPS proxy scores in white matter of the right premotor/motor/somatosensory/supramarginal gyrus regions, which are associated with empathy, theory of mind, primary and secondary somatosensory processing. Region of interest (ROI) analysis, based-on previous fMRI results and Freesurfer atlas-defined areas, showed small effect sizes, (+0.151 to -0.165) in white matter of the precuneus and inferior frontal gyrus. Other ROI effects were found in regions of the dorsal and ventral visual pathways and primary auditory cortex. The results reveal that in a large, diverse group of participants axonal microarchitectural differences can be identified with SPS traits that are subtle and in the range of typical behavior. The results suggest that the heightened sensory processing in people who show SPS may be influenced by the microstructure of white matter in specific neocortical regions. Although previous fMRI studies had identified most of these general neocortical regions, the DTI results put a new focus on brain areas related to attention and cognitive flexibility, empathy, emotion and low-level sensory processing, as in the primary sensory cortex. Psychological trait characterization may benefit from diffusion tensor imaging methodology by identifying influential brain systems for traits.

Abstract WMP40: Intra-arterial Mesenchymal Stem Cells in a Large Animal Endovascular Canine Stroke Model: Findings on Serial Diffusion Tensor Imaging

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Luis Guada ◽  
Pattany Pradip ◽  
Kevin Ramdas ◽  
Ryan Pafford ◽  
Gaurav Saigal ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Cell Therapy ◽  
Diffusion Tensor ◽  
Artery Occlusion ◽  
Experimental Models ◽  
Large Animal ◽  
White Matter Tracts ◽  
Neurologic Recovery ◽  
Adc Values

Background: Cell therapy is promising in rodent pre-clinical studies. Confirmation of efficacy of this novel approach in large animals is recommended. Diffusion Tensor Imaging (DTI) assesses white matter microstructure in the CNS using Fractional anisotropy (FA) and apparent diffusion coefficient (ADC). Diffusion Tensor Tractography (DTT) DTT produces a 3D representation of the white matter tracts (WMT) in which data are displayed on a colored map that helps to identify the integrity of the tracts selected under the region of Interest (ROI). The purpose of this study was to use DTI-DTT analysis, and correlate it with the neuro-assessment of dogs over one month after ipsilateral intra-arterial (IA) Mesenchymal Stem Cell (MSCs) 48 hours after a brain-stroke was reversible middle cerebral artery occlusion (rMCAo) Methods: Mongrel Hounds (n=5), aged 12-36 months, were included in this pilot study. rMCAo was induced via endovascular approach using a detachable helical ultra-coil over 35-80 min. MSCs (1-20 millions) were infused intra-arterially 48hrs post stroke in the ipsilesional cervical internal carotid. DTI-T images were obtained at 48h post rMCAo pre-IA cell delivery, 15 & 30 days. DTT was also generated. FA-ADC values of the right & left hemisphere and CST were determined. Weekly neuro-evaluations were performed using our canine neuro-scale Results: Our data suggest a correlation between the neurological recovery and improvement in the FA-ADC values (see figure). An increase in the caliber of corticospinal tracts ipsilateral to the stroke by day 30 compared to pre-injection was observed on the DTT reconstruction for two canines that showed neurological improvement ( see figure) Conclusions: Serial DTI-DTT imaging after IA cell therapy shows improvement in white matter tracts correlating with neurologic recovery. This supports further development of DTI-DTT biomarkers to measure neurologic recovery in experimental models as well as early clinical trials.

scholarly journals Indirect White Matter Pathways Are Associated With Treated Naming Improvement in Aphasia

2021 ◽  
pp. 154596832199905
Author(s):  
Janina Wilmskoetter ◽  
Julius Fridriksson ◽  
Alexandra Basilakos ◽  
Lorelei Phillip Johnson ◽  
Barbara Marebwa ◽  
...  
Keyword(s):  
White Matter ◽  
Treatment Outcomes ◽  
Inferior Frontal Gyrus ◽  
Brain Regions ◽  
Angular Gyrus ◽  
Middle Temporal Gyrus ◽  
Middle Temporal ◽  
Pars Opercularis ◽  
Left Hemisphere Stroke ◽  
Linear Regressions

Background White matter disconnection of language-specific brain regions associates with worse aphasia recovery. Despite a loss of direct connections, many stroke survivors may maintain indirect connections between brain regions. Objective To determine (1) whether preserved direct connections between language-specific brain regions relate to better poststroke naming treatment outcomes compared to no direct connections and (2) whether for individuals with a loss of direct connections, preserved indirect connections are associated with better treatment outcomes compared to individuals with no connections. Methods We computed structural whole-brain connectomes from 69 individuals with chronic left-hemisphere stroke and aphasia who completed a 3-week-long language treatment that was supplemented by either anodal transcranial direct current stimulation (A-tDCS) or sham stimulation (S-tDCS). We determined differences in naming improvement between individuals with direct, indirect, and no connections using 1-way analyses of covariance and multivariable linear regressions. Results Independently of tDCS modality, direct or indirect connections between the inferior frontal gyrus pars opercularis and angular gyrus were both associated with a greater increase in correct naming compared to no connections ( P = .027 and P = .039, respectively). Participants with direct connections between the inferior frontal gyrus pars opercularis and middle temporal gyrus who received S-tDCS and participants with indirect connections who received A-tDCS significantly improved in naming accuracy. Conclusions Poststroke preservation of indirect white matter connections is associated with better treated naming improvement in aphasia even when direct connections are damaged. This mechanistic information can be used to stratify and predict treated naming recovery in individuals with aphasia.

Tuberculoma – a great mimicker: can diffusion tensor imaging and tractography help?

2021 ◽  
pp. 028418512110636
Author(s):  
Beenish Khan ◽  
Rashmi Dixit ◽  
Anjali Prakash ◽  
Sunita Aggarwal
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Molecular Diffusion ◽  
Diffusion Tensor ◽  
Brain Parenchyma ◽  
Magnetic Resonance Scanner ◽  
Apparent Diffusion ◽  
Diffusion Tensor Images ◽  
Adc Values ◽  
Diffusion Tensor Imaging Dti

Background Central nervous system (CNS) tuberculomas often mimic tumors on conventional imaging, differentiation of which may not be possible without invasive tissue sampling. Diffusion tensor imaging (DTI), owing to its unrivalled property of characterizing molecular diffusion, may help in better lesion characterization and tractography may help understand the pattern of white matter involvement by tuberculomas. Purpose To estimate qualitative and quantitative diffusion tensor changes in brain tuberculomas and to evaluate patterns of white matter involvement using 3D tractography. Material and Methods Thirty patients with brain tuberculomas were evaluated on a 3-T magnetic resonance scanner. Diffusion tensor images were acquired along 20 non-colinear encoding directions with two b-values (b = 0, b = 1000). Regions of interest (ROIs) were drawn on quantitative fractional anisotropy (FA) and apparent diffusion coefficient (ADC) maps in the center of the tuberculoma and perilesional area. Similar ROIs were placed in contralateral hemispheres for comparison. Tractography maps were also generated. Results Mean FA in the center and perilesional area of tuberculomas were 0.098 ± 0.041 and 0.311 ± 0.135, respectively. ADC values in corresponding regions were 0.920 ± 0.272 ×10−3 mm2/s and 1.157 ± 0.277 ×10−3 mm2/s. These values were significantly different compared to contralateral similar brain parenchyma. Tractography revealed interruption of white fibers in the center with deviation of fibers at the periphery in the majority of tuberculomas with none showing infiltration of white matter described in tumors. Conclusion Significant qualitative as well as quantitative DTI changes were seen in tuberculoma and perilesional areas compared to contralateral hemisphere with tractography showing a pattern different from that described in tumors. These findings may help to differentiate tuberculomas from infiltrating tumors.

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