keyword
MENU ▼
Read by QxMD icon Read
search

tensor

keyword
https://www.readbyqxmd.com/read/28741711/diffusion-tensor-imaging-in-multiple-sclerosis-at-different-final-outcomes
#1
O Andersen, A Hildeman, M Longfils, H Tedeholm, B Skoog, W Tian, J Zhong, S Ekholm, L Novakova, B Runmarker, O Nerman, S E Maier
OBJECTIVES: Methods to evaluate the relative contributions of demyelination vs axonal degeneration over the long-term course of MS are urgently needed. We used magnetic resonance diffusion tensor imaging (DTI) to estimate degrees of demyelination and axonal degeneration in the corpus callosum (CC) in cases of MS with different final outcomes. MATERIALS AND METHODS: We determined DTI measures mean diffusivity (MD), fractional anisotropy (FA), and axial (AD) and radial (RD) diffusivities in the CC of 31 MS patients, of whom 13 presented a secondary progressive course, 11 a non-progressive course, and seven a monophasic course...
July 25, 2017: Acta Neurologica Scandinavica
https://www.readbyqxmd.com/read/28739393/rat-brain-digital-stereotaxic-white-matter-atlas-with-fine-tract-delineation-in-paxinos-space-and-its-automated-applications-in-dti-data-analysis
#2
Shengxiang Liang, Shang Wu, Qi Huang, Shaofeng Duan, Hua Liu, Yuxiao Li, Shujun Zhao, Binbin Nie, Baoci Shan
PURPOSE: To automatically analyze diffusion tensor images of the rat brain via both voxel-based and ROI-based approaches, we constructed a new white matter atlas of the rat brain with fine tracts delineation in the Paxinos and Watson space. MATERIALS AND METHODS: Unlike in previous studies, we constructed a digital atlas image from the latest edition of the Paxinos and Watson. This atlas contains 111 carefully delineated white matter fibers. A white matter network of rat brain based on anatomy was constructed by locating the intersection of all these tracts and recording the nuclei on the pathway of each white matter tract...
July 21, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28738366/neuroanatomical-correlates-of-hypophonia-in-subcortical-vascular-cognitive-impairment
#3
Ji Hye Yoon, Yisuh Ahn, Sook Hui Kim, Juhee Chin, Seongbeom Park, Duk L Na
BACKGROUND/AIMS: Early detection and intervention may alter the disease course of subcortical vascular cognitive impairment (SVCI). Patients with SVCI have white matter ischemia that disrupts connections between the cortex and subcortical gray matter and therefore manifest various symptoms such as motor disturbances and behavioral/cognitive dysfunction. Reduced vocal loudness, or hypophonia, is one of the common motor symptoms of SVCI, but few studies have systematically investigated it in this patient population...
July 24, 2017: European Neurology
https://www.readbyqxmd.com/read/28738061/magnetic-resonance-imaging-and-tensor-based-morphometry-in-the-mptp-non-human-primate-model-of-parkinson-s-disease
#4
Michel Modo, William R Crum, Madeline Gerwig, Anthony C Vernon, Priya Patel, Michael J Jackson, Sarah Rose, Peter Jenner, Mahmoud M Iravani
Parkinson's disease (PD) is the second most common neurodegenerative disorder producing a variety of motor and cognitive deficits with the causes remaining largely unknown. The gradual loss of the nigrostriatal pathway is currently considered the pivotal pathological event. To better understand the progression of PD and improve treatment management, defining the disease on a structural basis and expanding brain analysis to extra-nigral structures is indispensable. The anatomical complexity and the presence of neuromelanin, make the use of non-human primates an essential element in developing putative imaging biomarkers of PD...
2017: PloS One
https://www.readbyqxmd.com/read/28736521/group-level-progressive-alterations-in-brain-connectivity-patterns-revealed-by-diffusion-tensor-brain-networks-across-severity-stages-in-alzheimer-s-disease
#5
Javier Rasero, Carmen Alonso-Montes, Ibai Diez, Laiene Olabarrieta-Landa, Lakhdar Remaki, Iñaki Escudero, Beatriz Mateos, Paolo Bonifazi, Manuel Fernandez, Juan Carlos Arango-Lasprilla, Sebastiano Stramaglia, Jesus M Cortes
Alzheimer's disease (AD) is a chronically progressive neurodegenerative disease highly correlated to aging. Whether AD originates by targeting a localized brain area and propagates to the rest of the brain across disease-severity progression is a question with an unknown answer. Here, we aim to provide an answer to this question at the group-level by looking at differences in diffusion-tensor brain networks. In particular, making use of data from Alzheimer's Disease Neuroimaging Initiative (ADNI), four different groups were defined (all of them matched by age, sex and education level): G1 (N1 = 36, healthy control subjects, Control), G2 (N2 = 36, early mild cognitive impairment, EMCI), G3 (N3 = 36, late mild cognitive impairment, LMCI) and G4 (N4 = 36, AD)...
2017: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/28736471/comparison-of-multi-fiber-reproducibility-of-pas-mri-and-q-ball-with-empirical-multiple-b-value-hardi
#6
Vishwesh Nath, Kurt G Schilling, Justin A Blaber, Zhaohua Ding, Adam W Anderson, Bennett A Landman
Crossing fibers are prevalent in human brains and a subject of intense interest for neuroscience. Diffusion tensor imaging (DTI) can resolve tissue orientation but is blind to crossing fibers. Many advanced diffusion-weighted magnetic resolution imaging (MRI) approaches have been presented to extract crossing-fibers from high angular resolution diffusion imaging (HARDI), but the relative sensitivity and specificity of approaches remains unclear. Here, we examine two leading approaches (PAS and q-ball) in the context of a large-scale, single subject reproducibility study...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28735913/gray-matter-abnormalities-of-the-dorsal-posterior-cingulate-in-sleep-walking
#7
Anna Heidbreder, Ambra Stefani, Elisabeth Brandauer, Ruth Steiger, Christian Kremser, Elke R Gizewski, Peter Young, Werner Poewe, Birgit Högl, Christoph Scherfler
OBJECTIVE: This study aimed to determine whether voxel-based analysis of T1 weighted magnetic resonance imaging (MRI) and diffusion tensor imaging is able to detect alterations of gray and white matter morphometry as well as measures of mean diffusivity and fractional anisotropy in patients with non-rapid eye movement parasomnia. METHODS: 3 Tesla MRI was performed in 14 drug-free, polysomnography-confirmed adult patients with non-rapid eye movement parasomnia (age: 29 ± 4...
August 2017: Sleep Medicine
https://www.readbyqxmd.com/read/28734457/total-lower-lip-and-chin-reconstruction-with-radial-forearm-free-flap-a-novel-approach
#8
Eliza H Dewey, Ansley M Roche, Cathy L Lazarus, Mark L Urken
BACKGROUND: The management of large chin and lower lip defects is challenging due to this facial subunit's tremendous functional and aesthetic importance. Specific methods for total lower lip and mentum reconstruction are not well chronicled. Aesthetic and functional goals of this reconstruction include restoration of oral competence by maintaining lower lip height, vermilion reestablishment, color-matched skin introduction to the chin, sensation restoration, and ideally restoration of dynamic activity to the lower lip...
July 8, 2017: American Journal of Otolaryngology
https://www.readbyqxmd.com/read/28734309/universal-two-dimensional-characteristics-in-perovskite-type-oxyhydrides-atio2h-a-li-na-k-rb-cs
#9
Nobuya Sato, Ryosuke Akashi, Shinji Tsuneyuki
A series of unsynthesized perovskite-type oxyhydrides ATiO2H (A = Li, Na, K, Rb, Cs) are investigated by the density functional calculations. These oxyhydrides are stable in the sense of the formation energies for some possible synthesis reactions. They are crystallized into quite similar crystal structures with the long c-axis, and the corner-sharing TiO4H2 octahedra of the ideal perovskite-type structure are deformed into the 5-fold coordinated titanium atoms with the OH plane and the apical oxygen atoms...
July 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28734017/evaluation-of-the-impact-of-strain-correction-on-the-orientation-of-cardiac-diffusion-tensors-with-in-vivo-and-ex-vivo-porcine-hearts
#10
Pedro F Ferreira, Sonia Nielles-Vallespin, Andrew D Scott, Ranil de Silva, Philip J Kilner, Daniel B Ennis, Daniel A Auger, Jonathan D Suever, Xiaodong Zhong, Bruce S Spottiswoode, Dudley J Pennell, Andrew E Arai, David N Firmin
PURPOSE: To evaluate the importance of strain-correcting stimulated echo acquisition mode echo-planar imaging cardiac diffusion tensor imaging. METHODS: Healthy pigs (n = 11) were successfully scanned with a 3D cine displacement-encoded imaging with stimulated echoes and a monopolar-stimulated echo-planar imaging diffusion tensor imaging sequence at 3 T during diastasis, peak systole, and strain sweet spots in a midventricular short-axis slice. The same diffusion tensor imaging sequence was repeated ex vivo after arresting the hearts in either a relaxed (KCl-induced) or contracted (BaCl2 -induced) state...
July 21, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28733941/assessment-of-gray-and-white-matter-structural-alterations-in-migraineurs-without-aura
#11
Jilei Zhang, Yi-Lan Wu, Jingjing Su, Qian Yao, Mengxing Wang, Ge-Fei Li, Rong Zhao, Yan-Hui Shi, Ying Zhao, Qiting Zhang, Haifeng Lu, Shuai Xu, Zhaoxia Qin, Guo-Hong Cui, Jianqi Li, Jian-Ren Liu, Xiaoxia Du
BACKGROUND: Migraine constitute a disorder characterized by recurrent headaches, and have a high prevalence, a high socio-economic burden and severe effects on quality of life. Our previous fMRI study demonstrated that some brain regions are functional alterations in migraineurs. As the function of the human brain is related to its structure, we further investigated white and gray matter structural alterations in migraineurs. METHODS: In current study, we used surface-based morphometry, voxel-based morphometry and diffusion tensor imaging analyses to detect structural alterations of the white matter and gray matter in 32 migraineurs without aura compared with 32 age- and gender-matched healthy controls...
December 2017: Journal of Headache and Pain
https://www.readbyqxmd.com/read/28732673/expanding-the-horizons-for-structural-analysis-of-fully-protonated-protein-assemblies-by-nmr-spectroscopy-at-mas-frequencies-above-100%C3%A2-khz
#12
Jochem Struppe, Caitlin M Quinn, Manman Lu, Mingzhang Wang, Guangjin Hou, Xingyu Lu, Jodi Kraus, Loren B Andreas, Jan Stanek, Daniela Lalli, Anne Lesage, Guido Pintacuda, Werner Maas, Angela M Gronenborn, Tatyana Polenova
The recent breakthroughs in NMR probe technologies resulted in the development of MAS NMR probes with rotation frequencies exceeding 100 kHz. Herein, we explore dramatic increases in sensitivity and resolution observed at MAS frequencies of 110-111 kHz in a novel 0.7 mm HCND probe that enable structural analysis of fully protonated biological systems. Proton- detected 2D and 3D correlation spectroscopy under such conditions requires only 0.1-0.5 mg of sample and a fraction of time compared to conventional (13)C-detected experiments...
July 3, 2017: Solid State Nuclear Magnetic Resonance
https://www.readbyqxmd.com/read/28732285/infrared-dispersion-analysis-and-raman-scattering-spectra-of-taurine-single-crystals
#13
Roberto L Moreira, Ricardo P S M Lobo, Anderson Dias
A comprehensive set of optical vibrational modes of monoclinic taurine crystals was determined by Raman scattering, and infrared reflectivity and transmission spectroscopies. By using appropriate scattering/reflection geometries, the vibrational modes were resolved by polarization and the most relevant modes of the crystal could be assigned. In particular, we were able to review the symmetry of the gerade modes and to resolve ambiguities in the literature. Owing to the non-orthogonal character of Bu modes in monoclinic crystals (lying on the optic axial plane), we carried out a generalized Lorentz dispersion analysis consisting of simultaneous adjust of infrared-reflectivity spectra at various light polarization angles...
July 14, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28731760/steady-states-of-infinite-size-dissipative-quantum-chains-via-imaginary-time-evolution
#14
Adil A Gangat, Te I, Ying-Jer Kao
Directly in the thermodynamic limit, we show how to combine local imaginary and real-time evolution of tensor networks to efficiently and accurately find the nonequilibrium steady states (NESSs) of one-dimensional dissipative quantum lattices governed by a local Lindblad master equation. The imaginary time evolution first bypasses any highly correlated portions of the real-time evolution trajectory by directly converging to the weakly correlated subspace of the NESS, after which, real-time evolution completes the convergence to the NESS with high accuracy...
July 7, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28731755/spacetime-symmetries-and-conformal-data-in-the-continuous-multiscale-entanglement-renormalization-ansatz
#15
Q Hu, G Vidal
The generalization of the multiscale entanglement renormalization ansatz (MERA) to continuous systems, or cMERA [Haegeman et al., Phys. Rev. Lett. 110, 100402 (2013)PRLTAO0031-900710.1103/PhysRevLett.110.100402], is expected to become a powerful variational ansatz for the ground state of strongly interacting quantum field theories. In this Letter, we investigate, in the simpler context of Gaussian cMERA for free theories, the extent to which the cMERA state |Ψ^{Λ}⟩ with finite UV cutoff Λ can capture the spacetime symmetries of the ground state |Ψ⟩...
July 7, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28731515/analysis-of-structure-function-network-decoupling-in-the-brain-systems-of-spastic-diplegic-cerebral-palsy
#16
Dongha Lee, Chongwon Pae, Jong Doo Lee, Eun Sook Park, Sung-Rae Cho, Min-Hee Um, Seung-Koo Lee, Maeng-Keun Oh, Hae-Jeong Park
Manifestation of the functionalities from the structural brain network is becoming increasingly important to understand a brain disease. With the aim of investigating the differential structure-function couplings according to network systems, we investigated the structural and functional brain networks of patients with spastic diplegic cerebral palsy with periventricular leukomalacia compared to healthy controls. The structural and functional networks of the whole brain and motor system, constructed using deterministic and probabilistic tractography of diffusion tensor magnetic resonance images and Pearson and partial correlation analyses of resting-state functional magnetic resonance images, showed differential embedding of functional networks in the structural networks in patients...
July 21, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28730720/microstructural-white-matter-brain-abnormalities-in-patients-with-idiopathic-fecal-incontinence
#17
J Muthulingam, S Haas, T M Hansen, S Laurberg, L Lundby, H S Jørgensen, A M Drewes, K Krogh, J B Frøkjaer
BACKGROUND: Abnormal central nervous system processing of visceral sensation may be a part of the pathogenesis behind idiopathic fecal incontinence (IFI). Our aim was to characterize brain differences in patients with IFI and healthy controls by means of structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). METHODS: In 21 female patients with IFI and 15 female healthy controls, whole-brain structural differences in gray matter volume (GMV), cortical thickness, and white matter tracts fractional anisotropy (FA) were quantified...
July 21, 2017: Neurogastroenterology and Motility: the Official Journal of the European Gastrointestinal Motility Society
https://www.readbyqxmd.com/read/28729939/feature-selective-temporal-prediction-of-alzheimer-s-disease-progression-using-hippocampus-surface-morphometry
#18
Sinchai Tsao, Niharika Gajawelli, Jiayu Zhou, Jie Shi, Jieping Ye, Yalin Wang, Natasha Leporé
INTRODUCTION: Prediction of Alzheimer's disease (AD) progression based on baseline measures allows us to understand disease progression and has implications in decisions concerning treatment strategy. To this end, we combine a predictive multi-task machine learning method (cFSGL) with a novel MR-based multivariate morphometric surface map of the hippocampus (mTBM) to predict future cognitive scores of patients. METHODS: Previous work has shown that a multi-task learning framework that performs prediction of all future time points simultaneously (cFSGL) can be used to encode both sparsity as well as temporal smoothness...
July 2017: Brain and Behavior
https://www.readbyqxmd.com/read/28729936/are-there-differences-in-brain-morphology-according-to-handedness
#19
Han Jang, Jae Youn Lee, Kang Il Lee, Kang Min Park
OBJECTIVE: This study aimed to investigate the differences in brain morphology according to handedness. MATERIALS AND METHODS: Forty-two healthy subjects were enrolled (21 right-handers and 21 nonright-handers). The two groups were classified according to the Edinburgh Handedness Inventory. Measures of cortical morphology, such as thickness, surface area, volume, and curvature, and the volumes of subcortical structures, such as the amygdala, caudate, hippocampus, globus pallidus, putamen, and thalamus, were compared between the groups according to handedness using whole-brain 3D T1-weighted MRI...
July 2017: Brain and Behavior
https://www.readbyqxmd.com/read/28729077/white-matter-microstructure-degenerates-in-patients-with-postherpetic-neuralgia
#20
Fuxiang Chen, Fuyong Chen, Zhanfang Shang, Yuan Shui, Guorong Wu, Chen Liu, Zhangya Lin, Yuanxiang Lin, Lianghong Yu, Dezhi Kang, Wei Tao, Yongjie Li
OBJECTIVE: The central mechanisms underlying postherpetic neuralgia (PHN) pain remain unknown. The primary purpose of this study was to identify microstructural white matter changes closely related to the PHN pain by means of diffusion tensor imaging (DTI) and tract-based spatial statistics (TBSS) analysis. METHODS: DTI data of the brains were obtained from 8 PHN patients and 8 healthy controls (HC) that were matched in age, gender, and educational level. DTI metrics, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD), were separately compared between the two groups using TBSS analysis to detect subtle microstructural changes...
July 17, 2017: Neuroscience Letters
keyword
keyword
87983
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"