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https://www.readbyqxmd.com/read/28433624/temporal-slice-registration-and-robust-diffusion-tensor-reconstruction-for-improved-fetal-brain-structural-connectivity-analysis
#1
Bahram Marami, Seyed Sadegh Mohseni Salehi, Onur Afacan, Benoit Scherrer, Caitlin K Rollins, Edward Yang, Judy A Estroff, Simon K Warfield, Ali Gholipour
Diffusion weighted magnetic resonance imaging, or DWI, is one of the most promising tools for the analysis of neural microstructure and the structural connectome of the human brain. The application of DWI to map early development of the human connectome in-utero, however, is challenged by intermittent fetal and maternal motion that disrupts the spatial correspondence of data acquired in the relatively long DWI acquisitions. Fetuses move continuously during DWI scans. Reliable and accurate analysis of the fetal brain structural connectome requires careful compensation of motion effects and robust reconstruction to avoid introducing bias based on the degree of fetal motion...
April 19, 2017: NeuroImage
https://www.readbyqxmd.com/read/28418197/body-mass-index-associates-with-white-matter-microstructure-in-bipolar-depression
#2
Elena Mazza, Sara Poletti, Irene Bollettini, Clara Locatelli, Andrea Falini, Cristina Colombo, Francesco Benedetti
OBJECTIVES: Obesity has been reported in over 60% of bipolar disorder (BD) patients. It worsens the severity of illness, and influences cognition and functional outcomes. White matter (WM) abnormalities are one of the most consistently reported findings in neuroimaging studies of BD. We hypothesized that body mass index (BMI) could correlate with WM integrity in bipolar patients. METHODS: We evaluated BMI in a sample of 164 depressed patients affected by BD. We performed whole-brain tract-based spatial statistics with threshold-free cluster enhancement for the diffusion tensor imaging (DTI) measures of WM integrity: fractional anisotropy; axial, radial, and mean diffusivity...
April 18, 2017: Bipolar Disorders
https://www.readbyqxmd.com/read/28413981/default-mode-network-connectivity-and-related-white-matter-disruption-in-type-2-diabetes-mellitus-patients-concurrent-with-amnestic-mild-cognitive-impairment
#3
Di Qi, Ailin Wang, Yaojing Chen, Kewei Chen, Sisi Zhang, Junying Zhang, Xin Li, Lin Ai, Zhanjun Zhang
BACKGROUND: As a risk factor for Alzheimer's disease (AD), Type 2 diabetes mellitus (T2DM) itself causes cognitive impairment and has higher prevalence of mild cognitive impairment (MCI). OBJECTIVE: The aim of this study was to explore the cognition especially the episodic memory difference, the DMN functional connectivity and DMN-related white matter integrity in patients with both T2DM and amnestic MCI (T2DM-MCI) as compared to patients with T2DM only. METHOD: Focusing especially on T2DM population, we investigated the default mode network (DMN) through resting functional magnetic resonance imaging among 22 elderly T2DM-MCI patients and 24 elderly T2DM patients...
April 17, 2017: Current Alzheimer Research
https://www.readbyqxmd.com/read/28409964/gapless-spin-liquid-ground-state-in-the-s-1-2-kagome-antiferromagnet
#4
H J Liao, Z Y Xie, J Chen, Z Y Liu, H D Xie, R Z Huang, B Normand, T Xiang
The defining problem in frustrated quantum magnetism, the ground state of the nearest-neighbor S=1/2 antiferromagnetic Heisenberg model on the kagome lattice, has defied all theoretical and numerical methods employed to date. We apply the formalism of tensor-network states, specifically the method of projected entangled simplex states, which combines infinite system size with a correct accounting for multipartite entanglement. By studying the ground-state energy, the finite magnetic order appearing at finite tensor bond dimensions, and the effects of a next-nearest-neighbor coupling, we demonstrate that the ground state is a gapless spin liquid...
March 31, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28388468/evaluating-the-diagnostic-utility-of-applying-a-machine-learning-algorithm-to-diffusion-tensor-mri-measures-in-individuals-with-major-depressive-disorder
#5
David M Schnyer, Peter C Clasen, Christopher Gonzalez, Christopher G Beevers
Using MRI to diagnose mental disorders has been a long-term goal. Despite this, the vast majority of prior neuroimaging work has been descriptive rather than predictive. The current study applies support vector machine (SVM) learning to MRI measures of brain white matter to classify adults with Major Depressive Disorder (MDD) and healthy controls. In a precisely matched group of individuals with MDD (n =25) and healthy controls (n =25), SVM learning accurately (74%) classified patients and controls across a brain map of white matter fractional anisotropy values (FA)...
March 23, 2017: Psychiatry Research
https://www.readbyqxmd.com/read/28386486/thalamocortical-connectivity-and-microstructural-changes-in-congenital-and-late-blindness
#6
N H Reislev, T B Dyrby, H R Siebner, H Lundell, M Ptito, R Kupers
There is ample evidence that the occipital cortex of congenitally blind individuals processes nonvisual information. It remains a debate whether the cross-modal activation of the occipital cortex is mediated through the modulation of preexisting corticocortical projections or the reorganisation of thalamocortical connectivity. Current knowledge on this topic largely stems from anatomical studies in animal models. The aim of this study was to test whether purported changes in thalamocortical connectivity in blindness can be revealed by tractography based on diffusion-weighted magnetic resonance imaging...
2017: Neural Plasticity
https://www.readbyqxmd.com/read/28383490/seed-location-impacts-whole-brain-structural-network-comparisons-between-healthy-elderly-and-individuals-with-alzheimer-s-disease
#7
Lauren Zajac, Bang-Bon Koo, Corinna M Bauer, Ron Killiany, Behalf Of The Alzheimer's Disease Neuroimaging Initiative
Whole-brain networks derived from diffusion tensor imaging (DTI) data require the identification of seed and target regions of interest (ROIs) to assess connectivity patterns. This study investigated how initiating tracts from gray matter (GM) or white matter (WM) seed ROIs impacts (1) structural networks constructed from DTI data from healthy elderly (control) and individuals with Alzheimer's disease (AD) and (2) between-group comparisons using these networks. DTI datasets were obtained from the Alzheimer's disease Neuroimaging Initiative database...
April 6, 2017: Brain Sciences
https://www.readbyqxmd.com/read/28383028/3d-lattice-distortions-and-defect-structures-in-ion-implanted-nano-crystals
#8
Felix Hofmann, Edmund Tarleton, Ross J Harder, Nicholas W Phillips, Pui-Wai Ma, Jesse N Clark, Ian K Robinson, Brian Abbey, Wenjun Liu, Christian E Beck
Focussed Ion Beam (FIB) milling is a mainstay of nano-scale machining. By manipulating a tightly focussed beam of energetic ions, often gallium (Ga(+)), FIB can sculpt nanostructures via localised sputtering. This ability to cut solid matter on the nano-scale revolutionised sample preparation across the life, earth and materials sciences. Despite its widespread usage, detailed understanding of the FIB-induced structural damage, intrinsic to the technique, remains elusive. Here we examine the defects caused by FIB in initially pristine objects...
April 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28378878/network-evolution-in-mesial-temporal-lobe-epilepsy-revealed-by-diffusion-tensor-imaging
#9
Helen Wang, Yuegao Huang, Daniel Coman, Reshma Munbodh, Roni Dhaher, Hitten P Zaveri, Fahmeed Hyder, Tore Eid
OBJECTIVE: The objective of the present study is to identify novel, time-indexed imaging biomarkers of epileptogenesis in mesial temporal lobe epilepsy (MTLE). METHODS: We used high-resolution brain diffusion tensor imaging (DTI) of the translationally relevant methionine sulfoximine (MSO) brain infusion model of MTLE. MSO inhibits astroglial glutamine synthetase, which is deficient in the epileptogenic hippocampal formation of patients with MTLE. MSO-infused (epileptogenic) rats were compared with phosphate-buffered saline (PBS)-infused (nonepileptogenic) rats at early (3-4 days) and late (6-9 weeks) time points during epileptogenesis...
April 5, 2017: Epilepsia
https://www.readbyqxmd.com/read/28368642/loop-optimization-for-tensor-network-renormalization
#10
Shuo Yang, Zheng-Cheng Gu, Xiao-Gang Wen
We introduce a tensor renormalization group scheme for coarse graining a two-dimensional tensor network that can be successfully applied to both classical and quantum systems on and off criticality. The key innovation in our scheme is to deform a 2D tensor network into small loops and then optimize the tensors on each loop. In this way, we remove short-range entanglement at each iteration step and significantly improve the accuracy and stability of the renormalization flow. We demonstrate our algorithm in the classical Ising model and a frustrated 2D quantum model...
March 17, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28365490/abnormal-structural-connectivity-between-the-basal-ganglia-thalamus-and-frontal-cortex-in-patients-with-disorders-of-consciousness
#11
Ling Weng, Qiuyou Xie, Ling Zhao, Ruibin Zhang, Qing Ma, Junjing Wang, Wenjie Jiang, Yanbin He, Yan Chen, Changhong Li, Xiaoxiao Ni, Qin Xu, Ronghao Yu, Ruiwang Huang
Consciousness loss in patients with severe brain injuries is associated with reduced functional connectivity of the default mode network (DMN), fronto-parietal network, and thalamo-cortical network. However, it is still unclear if the brain white matter connectivity between the above mentioned networks is changed in patients with disorders of consciousness (DOC). In this study, we collected diffusion tensor imaging (DTI) data from 13 patients and 17 healthy controls, constructed whole-brain white matter (WM) structural networks with probabilistic tractography...
March 10, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
https://www.readbyqxmd.com/read/28364425/sleep-disturbance-may-alter-white-matter-and-resting-state-functional-connectivities-in-parkinson-s-disease
#12
Seok Jong Chung, Yong-Ho Choi, Hunki Kwon, Yeong-Hun Park, Hyuk Jin Yun, Han Soo Yoo, Seock Hyeon Moon, Byoung Seok Ye, Young H Sohn, Jong-Min Lee, Phil Hyu Lee
Study Objectives: To clarify whether sleep disturbance would alter the patterns of structural and functional networks underlying cognitive dysfunction in patients with Parkinson's disease (PD). Methods: Among the 180 patients with nondemented PD in our cohort, 45 patients were classified as the group with sleep disturbance according to the 5-item scales for outcomes in Parkinson's disease nighttime scale. Based on propensity scores, another 45 PD patients without sleep disturbance were matched to this group...
March 1, 2017: Sleep
https://www.readbyqxmd.com/read/28361345/altered-structural-connectivity-of-pain-related-brain-network-in-burning-mouth-syndrome-investigation-by-graph-analysis-of-probabilistic-tractography
#13
Akihiko Wada, Takashi Shizukuishi, Junko Kikuta, Haruyasu Yamada, Yusuke Watanabe, Yoshiki Imamura, Takahiro Shinozaki, Ko Dezawa, Hiroki Haradome, Osamu Abe
PURPOSE: Burning mouth syndrome (BMS) is a chronic intraoral pain syndrome featuring idiopathic oral pain and burning discomfort despite clinically normal oral mucosa. The etiology of chronic pain syndrome is unclear, but preliminary neuroimaging research has suggested the alteration of volume, metabolism, blood flow, and diffusion at multiple brain regions. According to the neuromatrix theory of Melzack, pain sense is generated in the brain by the network of multiple pain-related brain regions...
March 30, 2017: Neuroradiology
https://www.readbyqxmd.com/read/28360430/sex-differences-in-the-influence-of-body-mass-index-on-anatomical-architecture-of-brain-networks
#14
A Gupta, E A Mayer, K Hamadani, R Bhatt, C Fling, M Alaverdyan, C Torgenson, C Ashe-McNalley, J D Van Horn, B Naliboff, K Tillisch, C P Sanmiguel, J S Labus
BACKGROUND/OBJECTIVE: The brain plays a central role in regulating ingestive behavior in obesity. Analogous to addiction behaviors, an imbalance in the processing of rewarding and salient stimuli results in maladaptive eating behaviors that override homeostatic needs. We performed network analysis based on graph theory to examine the association between body mass index (BMI) and network measures of integrity, information flow, and global communication (centrality) in reward, salience and sensorimotor regions, and to identify sex-related differences in these parameters...
March 31, 2017: International Journal of Obesity: Journal of the International Association for the Study of Obesity
https://www.readbyqxmd.com/read/28358656/dynamics-of-white-matter-plasticity-underlying-working-memory-training-multimodal-evidence-from-diffusion-mri-and-t2-relaxometry
#15
Claudia Metzler-Baddeley, Sonya Foley, Silvia de Santis, Cyril Charron, Adam Hampshire, Karen Caeyenberghs, Derek K Jones
Adaptive working memory (WM) training may lead to cognitive benefits that are associated with white matter plasticity in parietofrontal networks, but the underlying mechanisms remain poorly understood. We investigated white matter microstructural changes after adaptive WM training relative to a nonadaptive comparison group. Microstructural changes were studied in the superior longitudinal fasciculus, the main parietofrontal connection, and the cingulum bundle as a comparison pathway. MRI-based metrics were the myelin water fraction and longitudinal relaxation rate R1 from multicomponent T2 relaxometry (captured with the mcDESPOT approach) as proxy metrics of myelin, the restricted volume fraction from the composite hindered and restricted model of diffusion as an estimate of axon morphology, and fractional anisotropy and radial diffusivity from diffusion tensor imaging...
March 30, 2017: Journal of Cognitive Neuroscience
https://www.readbyqxmd.com/read/28356046/white-matter-integrity-in-subcortical-vascular-cognitive-impairment-a-multimodal-structural-mri-study
#16
Yao Wang, Wenwei Cao, Yawen Sun, Xue Chen, Weina Ding, Qun Xu, Yan Zhou, Jianrong Xu, Shiteng Suo
OBJECTIVE: To investigate the disruption of white matter (WM) integrity in patients with subcortical vascular cognitive impairment (SVCI) with multimodal structural magnetic resonance imaging (MRI), and to explore the relationships between WM damage, structural network disruptions, and general cognitive function decline. METHODS: Twenty-eight patients with SVCI and twenty control subjects underwent structural MRI scans and neuropsychological assessment. WM volume (WMV), WM hyperintensities (WMH), lacunar infarcts (LI), diffusion tensor imaging parameters and structural network characteristics were compared between two groups...
March 29, 2017: Current Alzheimer Research
https://www.readbyqxmd.com/read/28342207/genetic-effect-of-mthfr-c677t-polymorphism-on-the-structural-covariance-network-and-white-matter-integrity-in-alzheimer-s-disease
#17
Yu-Tzu Chang, Shih-Wei Hsu, Shih-Jen Tsai, Ya-Ting Chang, Chi-Wei Huang, Mu-En Liu, Nai-Ching Chen, Wen-Neng Chang, Jung-Lung Hsu, Chen-Chang Lee, Chiung-Chih Chang
The 677 C to T transition in the MTHFR gene is a genetic determinant for hyperhomocysteinemia. We investigated whether this polymorphism modulates gray matter (GM) structural covariance networks independently of white-matter integrity in patients with Alzheimer's disease (AD). GM structural covariance networks were constructed by 3D T1-magnetic resonance imaging and seed-based analysis. The patients were divided into two genotype groups: C homozygotes (n = 73) and T carriers (n = 62). Using diffusion tensor imaging and white-matter parcellation, 11 fiber bundle integrities were compared between the two genotype groups...
March 25, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28337409/network-degeneration-and-dysfunction-in-presymptomatic-c9orf72-expansion-carriers
#18
Suzee E Lee, Ana C Sias, Maria Luisa Mandelli, Jesse A Brown, Alainna B Brown, Anna M Khazenzon, Anna A Vidovszky, Theodore P Zanto, Anna M Karydas, Mochtar Pribadi, Deepika Dokuru, Giovanni Coppola, Dan H Geschwind, Rosa Rademakers, Maria Luisa Gorno-Tempini, Howard J Rosen, Bruce L Miller, William W Seeley
Hexanucleotide repeat expansions in C9ORF72 are the most common known genetic cause of familial and sporadic frontotemporal dementia and amyotrophic lateral sclerosis. Previous work has shown that patients with behavioral variant frontotemporal dementia due to C9ORF72 show salience and sensorimotor network disruptions comparable to those seen in sporadic behavioral variant frontotemporal dementia, but it remains unknown how early in the lifespan these and other changes in brain structure and function arise...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28334875/white-matter-changes-in-paediatric-multiple-sclerosis-and-monophasic-demyelinating-disorders
#19
Giulia Longoni, Robert A Brown, Parya MomayyezSiahkal, Colm Elliott, Sridar Narayanan, Amit Bar-Or, Ruth Ann Marrie, E Ann Yeh, Massimo Filippi, Brenda Banwell, Douglas L Arnold
Most children who experience an acquired demyelinating syndrome of the central nervous system will have a monophasic disease course, with no further clinical or radiological symptoms. A subset will be diagnosed with multiple sclerosis, a life-long disorder. Using linear mixed effects models we examined longitudinal diffusion properties of normal-appearing white matter in 505 serial scans of 132 paediatric participants with acquired demyelinating syndromes followed for a median of 4.4 years, many from first clinical presentation, and 106 scans of 80 healthy paediatric participants...
March 14, 2017: Brain: a Journal of Neurology
https://www.readbyqxmd.com/read/28330962/distinct-white-matter-alterations-following-severe-stroke-longitudinal-dti-study-in-neglect
#20
Roza M Umarova, Lena Beume, Marco Reisert, Christoph P Kaller, Stefan Klöppel, Irina Mader, Volkmar Glauche, Valerij G Kiselev, Marco Catani, Cornelius Weiller
OBJECTIVE: To distinguish white matter remodeling directly induced by stroke lesion from that evoked by remote network dysfunction, using spatial neglect as a model. METHODS: We examined 24 visual neglect/extinction patients and 17 control patients combining comprehensive analyses of diffusion tensor metrics and global fiber tracking with neuropsychological testing in the acute (6.3 ± 0.5 days poststroke) and chronic (134 ± 7 days poststroke) stroke phases. RESULTS: Compared to stroke controls, patients with spatial neglect/extinction displayed longitudinal white matter alterations with 2 defining signatures: (1) perilesional degenerative changes characterized by congruently reduced fractional anisotropy and increased radial diffusivity (RD), axial diffusivity, and mean diffusivity, all suggestive of direct axonal damage by lesion and therefore nonspecific for impaired attention network and (2) transneuronal changes characterized by an increased RD in contralesional frontoparietal and bilateral occipital connections, suggestive of primary periaxonal involvement; these changes were distinctly related to the degree of unrecovered neglect symptoms in chronic stroke, hence emerging as network-specific alterations...
March 22, 2017: Neurology
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