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https://www.readbyqxmd.com/read/29793134/voxel-based-automated-detection-of-focal-cortical-dysplasia-lesions-using-diffusion-tensor-imaging-and-t2-weighted-mri-data
#1
Yanming Wang, Yawen Zhou, Huijuan Wang, Jin Cui, Benedictor Alexander Nguchu, Xufei Zhang, Bensheng Qiu, Xiaoxiao Wang, Mingwang Zhu
The aim of this study was to automatically detect focal cortical dysplasia (FCD) lesions in patients with extratemporal lobe epilepsy by relying on diffusion tensor imaging (DTI) and T2-weighted magnetic resonance imaging (MRI) data. We implemented an automated classifier using voxel-based multimodal features to identify gray and white matter abnormalities of FCD in patient cohorts. In addition to the commonly used T2-weighted image intensity feature, DTI-based features were also utilized. A Gaussian processes for machine learning (GPML) classifier was tested on 12 patients with FCD (8 with histologically confirmed FCD) scanned at 1...
May 21, 2018: Epilepsy & Behavior: E&B
https://www.readbyqxmd.com/read/29791961/getting-started-with-magnetic-resonance-neurography
#2
Gustav Andreisek, Nicolae V Bolog
This article provides a review of magnetic resonance neurography (MRN) and how to get started. It explains step by step how to establish MRN at an institution: how to set up MRN protocols, how to train technicians, what a report needs to contain, and how relevant findings should be communicated to the referring physician. Advanced imaging techniques such as diffusion tensor imaging are only briefly discussed at the end of the article because most of those techniques are difficult for beginners and are still not considered standard in the clinical routine...
July 2018: Seminars in Musculoskeletal Radiology
https://www.readbyqxmd.com/read/29791800/tip-enhanced-raman-scattering-from-nano-patterned-graphene-and-graphene-oxide
#3
Ashish Bhattarai, Andrey Krayev, Alexey Temiryazev, Dmitry Evplov, Kevin Thomas Crampton, Wayne P Hess, Patrick Z El Khoury
Tip-enhanced Raman spectroscopy (TERS) is particularly sensitive to analytes residing at plasmonic tip-sample nanojunctions, where the incident and scattered optical fields may be localized and optimally enhanced. However, the enhanced local electric fields in this so-called gap-mode TERS configuration are nominally orthogonal to the sample plane. As such, any given Raman active vibrational Eigenstate needs to have projections (of its polarizability derivative tensor elements) along the sample normal to be detectable via TERS...
May 23, 2018: Nano Letters
https://www.readbyqxmd.com/read/29791345/piezo-elasto-and-acousto-optic-properties-of-tl-3-ass-4-crystals
#4
Bohdan Mytsyk, Taras Kryvyy, Natalya Demyanyshyn, Oksana Mys, Iryna Martynyuk-Lototska, Oleksandr Kokhan, Rostyslav Vlokh
Complete matrices of piezo-optic and elasto-optic tensors are experimentally determined for Tl3 AsS4 crystals. It is revealed that the piezo-optic coefficients are very high, ∼10-11   N/m2 in the order of magnitude. This implies that Tl3 AsS4 can be referred to the best piezo-optic materials. The same concerns the elasto-optic coefficients, of which absolute values are in the interval 0.28-0.54. It is also found that, at the anisotropic and isotropic interactions with the slowest transverse and longitudinal acoustic waves, the acousto-optic figure of merit reaches extremely high values (1...
May 10, 2018: Applied Optics
https://www.readbyqxmd.com/read/29791077/alterations-of-brain-network-hubs-in-reflex-syncope-evidence-from-a-graph-theoretical-analysis-based-on-dti
#5
Bong Soo Park, Yoo Jin Lee, Jin-Han Park, Il Hwan Kim, Si Hyung Park, Ho-Joon Lee, Kang Min Park
OBJECTIVE: We evaluated global topology and organization of regional hubs in the brain networks and microstructural abnormalities in the white matter of patients with reflex syncope. METHODS: Twenty patients with reflex syncope and thirty healthy subjects were recruited, and they underwent diffusion tensor imaging (DTI) scans. Graph theory was applied to obtain network measures based on extracted DTI data, using DSI Studio. We then investigated differences in the network measures between the patients with reflex syncope and the healthy subjects...
May 23, 2018: Brain and Behavior
https://www.readbyqxmd.com/read/29790915/yamda-thousandfold-speedup-of-em-based-motif-discovery-using-deep-learning-libraries-and-gpu
#6
Daniel Quang, Yuanfang Guan, Stephen C J Parker
Motivation: Motif discovery in large biopolymer sequence datasets can be computationally demanding, presenting significant challenges for discovery in omics research. MEME, arguably one of the most popular motif discovery software, takes quadratic time with respect to dataset size, leading to excessively long runtimes for large datasets. Therefore, there is a demand for fast programs that can generate results of the same quality as MEME. Results: Here we describe YAMDA, a highly scalable motif discovery software package...
May 22, 2018: Bioinformatics
https://www.readbyqxmd.com/read/29790085/white-matter-microstructure-in-bipolar-disorder-is-influenced-by-the-interaction-between-a-glutamate-transporter-eaat1-gene-variant-and-early-stress
#7
Sara Poletti, Irene Bollettini, Cristina Lorenzi, Alice Vitali, Silvia Brioschi, Alessandro Serretti, Cristina Colombo, Francesco Benedetti
Glutamate is the principal excitatory neurotransmitter in the central nervous system. In mature brains, it is critically involved in neuroplasticity and, at high levels, neurotoxicity. The concentrations of glutamate in the extracellular space are maintained at low physiological levels by molecular glutamate transporters (excitatory amino acid transporters-EAATs). Adverse childhood experiences (ACEs) are highly reported in bipolar disorder (BD) and interact with the glutamatergic system in the brain. The aim of the study is to investigate the effect of a glutamate transporter polymorphism EAAT2-181A > C (rs4354668) and exposure to ACE on white matter microstructure in patients with BD...
May 22, 2018: Molecular Neurobiology
https://www.readbyqxmd.com/read/29789888/diffusion-tensor-imaging-in-acute-pyelonephritis-in-children
#8
Mickaël Lair, Mariette Renaux-Petel, Adnan Hassani, Yohann Cruypeninck, Ioana Vasies, Agnès Liard, Jean-Nicolas Dacher, Pierre-Hugues Vivier
BACKGROUND: Diffusion-weighted imaging plays a key role in the imaging of acute pyelonephritis by MRI. However the use of respiratory triggering is challenging and time-consuming in children. Diffusion tensor imaging without respiratory triggering might provide satisfying images of the moving kidneys. OBJECTIVE: To compare mean diffusivity diffusion tensor images obtained with free breathing with diffusion-weighted images obtained with respiratory triggering. MATERIALS AND METHODS: Thirty-one children with suspected acute pyelonephritis underwent axial diffusion tensor imaging acquisition with free breathing and axial and coronal diffusion-weighted imaging acquisitions with respiratory triggering...
May 22, 2018: Pediatric Radiology
https://www.readbyqxmd.com/read/29786476/orthopedic-injured-versus-uninjured-comparison-groups-for-neuroimaging-research-in-mild-traumatic-brain-injury
#9
Elisabeth A Wilde, Ashley L Ware, Xiaoqi Li, Trevor C Wu, Stephen R McCauley, Amanda Barnes, Mary Newsome, Brian Biekman, Jill V Hunter, Zili Chu, Harvey Levin
To address controversy surrounding the most appropriate comparison group for mild traumatic brain injury (mTBI) research, mTBI patients aged 12-30 years were compared to an extracranial orthopedic injury (OI) patient group and an uninjured, typically-developing (TD) participant group with comparable demographic backgrounds. Injured participants underwent subacute (within 96 hours) and late (3 months) diffusion tensor imaging (DTI); TD controls underwent DTI once. Group differences in fractional anisotropy (FA) and mean diffusivity (MD) of commonly studied white matter tracts were assessed...
May 22, 2018: Journal of Neurotrauma
https://www.readbyqxmd.com/read/29786464/what-can-we-learn-from-diffusion-tensor-imaging-from-a-large-traumatic-brain-injury-cohort-white-matter-integrity-and-its-relationship-with-outcome
#10
Ana M Castaño-Leon, Marta Cicuendez, Blanca Navarro, Pablo M Munarriz, Santiago Cepeda, Igor Paredes, Amaya Hilario, Ana Ramos, Pedro Antonio Gomez, Alfonso Lagares
Traumatic axonal injury (TAI) contributes significantly to mortality and morbidity after traumatic brain injury (TBI) but its identification is still a diagnostic challenge because of the limitations of conventional imaging techniques to characterized it. Diffusion tensor imaging (DTI) can indirectly identify areas of damaged white matter (WM) integrity by detecting water molecules diffusion alterations. Therefore, DTI may improve detection and description of TAI lesions after TBI. We have obtained DTI data from 217 patients with moderate to severe TBI acquired at median 19 days after TBI were and patient DTI metrics were compared with data obtained from 58 age-matched healthy controls...
May 22, 2018: Journal of Neurotrauma
https://www.readbyqxmd.com/read/29786463/hybrid-diffusion-imaging-in-mild-traumatic-brain-injury
#11
Yu-Chien Wu, Sourajit Mitra Mustafi, Jaroslaw Harezlak, Chandana Kodiweera, Laura A Flashman, Thomas McAllister
Mild traumatic brain injury (mTBI) is an important public health problem. Although conventional medical imaging techniques can detect moderate-to-severe injuries, they are relatively insensitive to mTBI. In this study, we used hybrid diffusion imaging (HYDI) to detect white-matter alterations in nineteen patients with mTBI and 23 other trauma-control patients. Within 15 days (SD=10) of brain injury, all subjects underwent magnetic-resonance HYDI and were assessed with battery of neuropsychological tests of sustained attention, memory, and executive function...
May 22, 2018: Journal of Neurotrauma
https://www.readbyqxmd.com/read/29785360/identical-patterns-of-cortico-efferent-tract-involvement-in-primary-lateral-sclerosis-and-amyotrophic-lateral-sclerosis-a-tract-of-interest-based-mri-study
#12
Hans-Peter Müller, Martin Gorges, Rebecca Kassubek, Johannes Dorst, Albert C Ludolph, Jan Kassubek
Background: There is an ongoing debate whether primary lateral sclerosis (PLS) should be regarded as an independent disease entity separate from amyotrophic lateral sclerosis (ALS) or as a slowly progressive variant of ALS. Objective: The study was designed to investigate specific white matter alterations in diffusion tensor imaging (DTI) data from PLS patients by a hypothesis-guided tract-of-interest-based approach compared with 'classical' ALS patients and healthy controls, in order to identify microstructural changes according to the neuropathologically defined ALS affectation pattern in vivo...
2018: NeuroImage: Clinical
https://www.readbyqxmd.com/read/29785359/white-matter-microstructure-white-matter-lesions-and-hypertension-an-examination-of-early-surrogate-markers-of-vascular-related-brain-change-in-midlife
#13
Thaddeus Haight, R Nick Bryan, Guray Erus, Meng-Kang Hsieh, Christos Davatzikos, Ilya Nasrallah, Mark D'Esposito, David R Jacobs, Cora Lewis, Pamela Schreiner, Stephen Sidney, Osorio Meirelles, Lenore J Launer
Objective: We examined imaging surrogates of white matter microstructural abnormalities which may precede white matter lesions (WML) and represent a relevant marker of cerebrovascular injury in adults in midlife. Methods: In 698 community-dwelling adults (mean age 50 years ±3.5 SD) from the Coronary Artery Risk Development in Young Adults (CARDIA) Brain MRI sub-study, WML were identified on structural MR and fractional anisotropy (FA), representing WM microstructural integrity, was derived using Diffusion Tensor Imaging...
2018: NeuroImage: Clinical
https://www.readbyqxmd.com/read/29785226/progressive-assessment-of-ischemic-injury-to-white-matter-using-diffusion-tensor-imaging-a-preliminary-study-of-a-macaque-model-of-stroke
#14
Xiaodong Zhang, Yumei Yan, Frank Tong, Chun-Xia Li, Benjamin Jones, Silun Wang, Yuguang Meng, E Chris Muly, Doty Kempf, Leonard Howell
Background: Previous Diffusion Tensor Imaging (DTI) studies have demonstrated the temporal evolution of stroke injury in grey matter and white matter can be characterized by DTI indices. However, it still remains not fully understood how the DTI indices of white matter are altered progressively during the hyperacute (first 6 hours) and acute stage of stroke (≤ 1 week). In the present study, DTI was employed to characterize the temporal evolution of infarction and white matter injury after stroke insult using a macaque model with permanent ischemic occlusion...
2018: Open Neuroimaging Journal
https://www.readbyqxmd.com/read/29781808/tensor-driven-extraction-of-developmental-features-from-varying-paediatric-eeg-datasets
#15
Eli Kinney-Lang, Loukianos Spyrou, Ahmed Ebied, Richard Fm Chin, Javier Escudero
Constant changes in developing children's brains can pose a challenge in EEG dependant technologies. Advancing signal processing methods to identify developmental differences in paediatric populations could help improve function and usability of such technologies. Taking advantage of the multi-dimensional structure of EEG data through tensor analysis may offer a framework for extracting relevant developmental features of paediatric datasets. A proof of concept is demonstrated through identifying latent developmental features in resting-state EEG...
May 21, 2018: Journal of Neural Engineering
https://www.readbyqxmd.com/read/29781583/altered-white-matter-connectivity-associated-with-visual-hallucinations-following-occipital-stroke
#16
Sara A Rafique, John R Richards, Jennifer K E Steeves
INTRODUCTION: Visual hallucinations that arise following vision loss stem from aberrant functional activity in visual cortices and an imbalance of activity across associated cortical and subcortical networks subsequent to visual pathway damage. We sought to determine if structural changes in white matter connectivity play a role in cases of chronic visual hallucinations associated with visual cortical damage. METHODS: We performed diffusion tensor imaging (DTI) and probabilistic fiber tractography to assess white matter connectivity in a patient suffering from continuous and disruptive phosphene (simple) visual hallucinations for more than 2 years following right occipital stroke...
May 21, 2018: Brain and Behavior
https://www.readbyqxmd.com/read/29780509/self-complementary-nickel-halides-enable-multifaceted-comparisons-of-intermolecular-halogen-bonds-fluoride-ligands-vs-other-halides
#17
Vargini Thangavadivale, Pedro M Aguiar, Naseralla A Jasim, Sarah J Pike, Dan A Smith, Adrian C Whitwood, Lee Brammer, Robin N Perutz
The syntheses of three series of complexes designed with self-complementary motifs for formation of halogen bonds between an iodotetrafluorophenyl ligand and a halide ligand at square-planar nickel are reported, allowing structural comparisons of halogen bonding between all four halides C6 F4 I···X-Ni (X = F, Cl, Br, I). In the series trans -[NiX(2,3,5,6-C6 F4 I)(PEt3 )2 ] 1pX and trans -[NiX(2,3,4,5-C6 F4 I)(PEt3 )2 ] (X = F, Cl, Br, I) 1oX , the iodine substituent on the benzene ring was positioned para and ortho to the metal, respectively...
April 21, 2018: Chemical Science
https://www.readbyqxmd.com/read/29779901/white-matter-disruptions-in-patients-with-bipolar-disorder
#18
Lucija Abramovic, Marco P M Boks, Annabel Vreeker, Sanne Verkooijen, Annet H van Bergen, Roel A Ophoff, René S Kahn, Neeltje E M van Haren
Bipolar disorder (BD) patients show aberrant white matter microstructure compared to healthy controls but little is known about the relation with clinical characteristics. We therefore investigated the relation of white matter microstructure with the main pharmacological treatments as well its relation with IQ. Patients with BD (N = 257) and controls (N = 167) underwent diffusion tensor imaging (DTI) and comprehensive clinically assessments including IQ estimates. DTI images were analyzed using tract-based spatial statistics...
May 17, 2018: European Neuropsychopharmacology: the Journal of the European College of Neuropsychopharmacology
https://www.readbyqxmd.com/read/29777918/sex-differences-in-the-spatial-distribution-of-bone-in-relation-to-incident-hip-fracture-findings-from-the-ages-reykjavik-study
#19
Elisa A Marques, Julio Carballido-Gamio, Vilmundur Gudnason, Gunnar Sigurdsson, Sigurdur Sigurdsson, Thor Aspelund, Kristin Siggeirsdottir, Lenore Launer, Gudny Eiriksdottir, Thomas Lang, Tamara B Harris
In this case-cohort study, we used data-driven computational anatomy approaches to assess within and between sex spatial differences in proximal femoral bone characteristics in relation to incident hip fracture. One hundred male and 234 female incident hip fracture cases, and 1047 randomly selected noncase subcohort participants (562 female) were chosen from the population-based AGES-Reykjavik study (mean age of 77 years). The baseline -i.e. before hip fracture- hip quantitative computed tomography scans of these subjects were analyzed using voxel-based morphometry, tensor-based morphometry, and surface-based statistical parametric mapping to assess the spatial distribution of volumetric bone mineral density (vBMD), internal structure, and cortical bone properties (thickness, vBMD and trabecular vBMD adjacent to the endosteal surface) of the proximal femur, respectively, in relation to incident hip fracture...
May 16, 2018: Bone
https://www.readbyqxmd.com/read/29776704/cerebellar-peduncle-injury-predicts-motor-impairments-in-preterm-infants-a-quantitative-tractography-study-at-term-equivalent-age
#20
Tatsuji Hasegawa, Kei Yamada, Takenori Tozawa, Tomohiro Chiyonobu, Sachiko Tokuda, Akira Nishimura, Hajime Hosoi, Masafumi Morimoto
PURPOSE: Cerebellar injury is well established as an important finding in preterm infants with cerebral palsy (CP). In this study, we investigated associations between injury to the cerebellar peduncles and motor impairments in preterm infants using quantitative tractography at term-equivalent age, which represents an early phase before the onset of motor impairments. METHODS: We studied 64 preterm infants who were born at <33 weeks gestational age. These infants were divided into three groups: CP, Non-CP (defined as infants with periventricular leukomalacia but having normal motor function), and a Normal group...
May 15, 2018: Brain & Development
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