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https://www.readbyqxmd.com/read/28515708/disrupted-structural-and-functional-networks-and-their-correlation-with-alertness-in-right-temporal-lobe-epilepsy-a-graph-theory-study
#1
Wenyu Jiang, Jianping Li, Xuemei Chen, Wei Ye, Jinou Zheng
Previous studies have shown that temporal lobe epilepsy (TLE) involves abnormal structural or functional connectivity in specific brain areas. However, limited comprehensive studies have been conducted on TLE associated changes in the topological organization of structural and functional networks. Additionally, epilepsy is associated with impairment in alertness, a fundamental component of attention. In this study, structural networks were constructed using diffusion tensor imaging tractography, and functional networks were obtained from resting-state functional MRI temporal series correlations in 20 right temporal lobe epilepsy (rTLE) patients and 19 healthy controls...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28499604/iron-oxide-nanoparticles-in-vivo-in-vitro-biomedical-applications-and-in-silico-studies
#2
REVIEW
Miroslava Nedyalkova, Borjana Donkova, Julia Romanova, George Tzvetkov, Sergio Madurga, Vasil Simeonov
The review presents a broad overview of the biomedical applications of surface functionalized iron oxide nanoparticles (IONPs) as magnetic resonance imaging (MRI) agents for sensitive and precise diagnosis tool and synergistic combination with other imaging modalities. Then, the recent progress in therapeutic applications, such as hyperthermia is discussed and the available toxicity data of magnetic nanoparticles concerning in vitro and in vivo biomedical applications are addressed. This review also presents the available computer models using molecular dynamics (MD), Monte Carlo (MC) and density functional theory (DFT), as a basis for a complete understanding of the behaviour and morphology of functionalized IONPs, for improving NPs surface design and expanding the potential applications in nanomedicine...
May 3, 2017: Advances in Colloid and Interface Science
https://www.readbyqxmd.com/read/28486817/altered-network-topology-in-patients-with-primary-brain-tumors-after-fractionated-radiotherapy
#3
Naeim Bahrami, Tyler M Seibert, Roshan Karunamuni, Hauke Bartsch, AnithaPriya Krishna, Nikdokht Farid, Jona A Hattangadi-Gluth, Carrie R McDonald
Radiation therapy (RT) is a critical treatment modality for patients with brain tumors, though it can cause adverse effects. Recent data suggests that brain RT is associated with dose-dependent cortical atrophy which could disrupt neocortical networks. This study examines whether brain RT affects structural network properties in brain tumor patients. We applied graph theory to MRI-derived cortical thickness estimates of 54 brain tumor patients before and after RT. Cortical surfaces were parcellated into 68 regions and correlation matrices were created for patients pre- and post-RT...
May 9, 2017: Brain Connectivity
https://www.readbyqxmd.com/read/28474385/disrupted-topological-organization-of-structural-networks-revealed-by-probabilistic-diffusion-tractography-in-tourette-syndrome-children
#4
Hongwei Wen, Yue Liu, Islem Rekik, Shengpei Wang, Jishui Zhang, Yue Zhang, Yun Peng, Huiguang He
Tourette syndrome (TS) is a childhood-onset neurobehavioral disorder. Although previous TS studies revealed structural abnormalities in distinct corticobasal ganglia circuits, the topological alterations of the whole-brain white matter (WM) structural networks remain poorly understood. Here, we used diffusion MRI probabilistic tractography and graph theoretical analysis to investigate the topological organization of WM networks in 44 drug-naive TS children and 41 age- and gender-matched healthy children. The WM networks were constructed by estimating inter-regional connectivity probability and the topological properties were characterized using graph theory...
May 5, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28466257/cortical-representation-of-pain-and-touch-evidence-from-combined-functional-neuroimaging-and-electrophysiology-in-non-human-primates
#5
REVIEW
Li Min Chen
Human functional MRI studies in acute and various chronic pain conditions have revolutionized how we view pain, and have led to a new theory that complex multi-dimensional pain experience (sensory-discriminative, affective/motivational, and cognitive) is represented by concurrent activity in widely-distributed brain regions (termed a network or pain matrix). Despite these breakthrough discoveries, the specific functions proposed for these regions remain elusive, because detailed electrophysiological characterizations of these regions in the primate brain are lacking...
May 2, 2017: Neuroscience Bulletin
https://www.readbyqxmd.com/read/28465264/quantitative-susceptibility-mapping-as-a-possible-tool-to-radiographically-diagnose-sentinel-headache-associated-with-intracranial-aneurysm-case-report
#6
Daichi Nakagawa, Cameron Cushing, Yasunori Nagahama, Lauren Allan, David Hasan
BACKGROUND: Sentinel headache (SH) is estimated to occur prior to rupture of an aneurysm in 15-60% of aneurysmal subarachnoid hemorrhage (aSAH) cases. Non-contrasted computed tomography (CT) of brain and lumbar puncture are both negative, by definition, in patients presenting with SH. One of the theories explaining this phenomenon is micro-hemorrhage (MH) from the aneurysm wall contributing to iron deposition in the interface between the aneurysm wall and brain parenchyma. Quantitative susceptibility mapping (QSM) is a recently introduced magnetic resonance imaging (MRI) technique that has been shown capable of localizing the deposition of paramagnetic metals, particularly ferric iron...
April 29, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28460243/optimal-control-design-of-preparation-pulses-for-contrast-optimization-in-mri
#7
Eric Van Reeth, Hélène Ratiney, Michael Tesch, Denis Grenier, Olivier Beuf, Steffen J Glaser, Dominique Sugny
This work investigates the use of MRI radio-frequency (RF) pulses designed within the framework of optimal control theory for image contrast optimization. The magnetization evolution is modeled with Bloch equations, which defines a dynamic system that can be controlled via the application of the Pontryagin Maximum Principle (PMP). This framework allows the computation of optimal RF pulses that bring the magnetization to a given state to obtain the desired contrast after acquisition. Creating contrast through the optimal manipulation of Bloch equations is a new way of handling contrast in MRI, which can explore the theoretical limits of the system...
April 21, 2017: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/28452522/imaging-local-diffusive-dynamics-using-diffusion-exchange-spectroscopy-mri
#8
Dan Benjamini, Michal E Komlosh, Peter J Basser
The movement of water between microenvironments presents a central challenge in the physics of soft matter and porous media. Diffusion exchange spectroscopy (DEXSY) is a powerful 2D nuclear magnetic resonance method for measuring such exchange, yet it is rarely used because of its long scan time requirements. Moreover, it has never been combined with magnetic resonance imaging (MRI). Using probability theory, we vastly reduce the required data, making DEXSY MRI feasible for the first time. Experiments are performed on a composite nerve tissue phantom with restricted and free water-exchanging compartments...
April 14, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28438464/association-of-medial-prefrontal-cortex-connectivity-with-consciousness-level-and-its-outcome-in-patients-with-acquired-brain-injury
#9
Xiaoyan Liu, Jingqi Li, Jian Gao, Zhen Zhou, Fanxia Meng, Gang Pan, Benyan Luo
Medial prefrontal cortex (mPFC) is usually known for participating in virtually all self related processing. However, few have investigated the role of mPFC in modulating conscious awareness. This study aimed to depict the relationship between the mPFC connectivity and the severity and outcome of the disorders of consciousness (DOC) among patients with acquired brain injury. Thirty-four patients with DOC (17 in a minimally conscious state and 17 in an unresponsive wakefulness syndrome/vegetative state) and 11 healthy controls were recruited, underwent clinical assessment and resting-state functional MRI scan, and were further followed up to evaluate recovery outcome using the Glasgow Outcome Scale...
April 21, 2017: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
https://www.readbyqxmd.com/read/28393659/variability-of-physiological-brain-perfusion-in-healthy-subjects-a-systematic-review-of-modifiers-considerations-for-multi-center-asl-studies
#10
Patricia Clement, Henk-Jan Mutsaerts, Lena Václavů, Eidrees Ghariq, Francesca B Pizzini, Marion Smits, Marjan Acou, Jorge Jovicich, Ritva Vanninen, Mervi Kononen, Roland Wiest, Egill Rostrup, António J Bastos-Leite, Elna-Marie Larsson, Eric Achten
Quantitative measurements of brain perfusion are influenced by perfusion-modifiers. Standardization of measurement conditions and correction for important modifiers is essential to improve accuracy and to facilitate the interpretation of perfusion-derived parameters. An extensive literature search was carried out for factors influencing quantitative measurements of perfusion in the human brain unrelated to medication use. A total of 58 perfusion modifiers were categorized into four groups. Several factors (e...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28374954/multifunctional-gadolinium-doped-mesoporous-tio2-nanobeads-photoluminescence-enhanced-spin-relaxation-and-reactive-oxygen-species-photogeneration-beneficial-for-cancer-diagnosis-and-treatment
#11
Roghayeh Imani, Ralf Dillert, Detlef W Bahnemann, Meysam Pazoki, Tomaž Apih, Veno Kononenko, Neža Repar, Veronika Kralj-Iglič, Gerrit Boschloo, Damjana Drobne, Tomas Edvinsson, Aleš Iglič
Materials with controllable multifunctional abilities for optical imaging (OI) and magnetic resonant imaging (MRI) that also can be used in photodynamic therapy are very interesting for future applications. Mesoporous TiO2 sub-micrometer particles are doped with gadolinium to improve photoluminescence functionality and spin relaxation for MRI, with the added benefit of enhanced generation of reactive oxygen species (ROS). The Gd-doped TiO2 exhibits red emission at 637 nm that is beneficial for OI and significantly improves MRI relaxation times, with a beneficial decrease in spin-lattice and spin-spin relaxation times...
April 4, 2017: Small
https://www.readbyqxmd.com/read/28370719/brain-structure-and-organization-five-decades-after-childhood-onset-epilepsy
#12
Camille Garcia-Ramos, Sam Bobholz, Kevin Dabbs, Bruce Hermann, Juho Joutsa, Juha O Rinne, Mira Karrasch, Vivek Prabhakaran, Shlomo Shinnar, Matti Sillanpää
The purpose of this project was to characterize brain structure and organization in persons with active and remitted childhood onset epilepsy 50 years after diagnosis compared with healthy controls. Participants from a population-based investigation of uncomplicated childhood onset epilepsy were followed up 5 decades later. Forty-one participants had a history of childhood onset epilepsy (mean age of onset = 5.2 years, current chronological age = 56.0 years) and were compared with 48 population-based controls (mean age = 55...
June 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28363836/multi-echo-fmri-a-review-of-applications-in-fmri-denoising-and-analysis-of-bold-signals
#13
Prantik Kundu, Valerie Voon, Priti Balchandani, Michael V Lombardo, Benedikt A Poser, Peter Bandettini
In recent years the field of fMRI research has enjoyed expanded technical abilities related to resolution, as well as use across many fields of brain research. At the same time, the field has also dealt with uncertainty related to many known and unknown effects of artifact in fMRI data. In this review we discuss an emerging fMRI technology, called multi-echo (ME)-fMRI, which focuses on improving the fidelity and interpretability of fMRI. Where the essential problem of standard single-echo fMRI is the indeterminacy of sources of signals, whether BOLD or artifact, this is not the case for ME-fMRI...
March 28, 2017: NeuroImage
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
#14
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...
May 2017: Neuroradiology
https://www.readbyqxmd.com/read/28333589/a-unified-theory-of-neuro-mri-data-shows-scale-free-nature-of-connectivity-modes
#15
Vitaly L Galinsky, Lawrence R Frank
A primary goal of many neuroimaging studies that use magnetic resonance imaging (MRI) is to deduce the structure-function relationships in the human brain using data from the three major neuro-MRI modalities: high-resolution anatomical, diffusion tensor imaging, and functional MRI. To date, the general procedure for analyzing these data is to combine the results derived independently from each of these modalities. In this article, we develop a new theoretical and computational approach for combining these different MRI modalities into a powerful and versatile framework that combines our recently developed methods for morphological shape analysis and segmentation, simultaneous local diffusion estimation and global tractography, and nonlinear and nongaussian spatial-temporal activation pattern classification and ranking, as well as our fast and accurate approach for nonlinear registration between modalities...
March 23, 2017: Neural Computation
https://www.readbyqxmd.com/read/28323405/oxygen-vacancy-enables-markedly-enhanced-magnetic-resonance-imaging-guided-photothermal-therapy-of-a-gd-3-doped-contrast-agent
#16
Dalong Ni, Jiawen Zhang, Jing Wang, Ping Hu, Yingying Jin, Zhongmin Tang, Zhenwei Yao, Wenbo Bu, Jianlin Shi
Gd(3+)-based contrast agents (CAs) are the most prevailing and widely used for enhanced magnetic resonance imaging (MRI). Numbers of approaches have been developed to regulate the key parameters in order to obtain high-relaxivity CAs, according to the classic Solomon-Bloembergen-Morgen theory. Herein, a method of controlling oxygen vacancies in inorganic nanosized CAs has been developed for largely accelerated proton relaxation to obtain a high r1 value. Such a strategy is verified on oxygen-deficient PEG-NaxGdWO3 nanorods, which exhibit a remarkable r1 value up to 80 mM(-1) s(-1) (at 0...
April 25, 2017: ACS Nano
https://www.readbyqxmd.com/read/28323202/enhanced-structural-connectivity-within-a-brain-sub-network-supporting-working-memory-and-engagement-processes-after-cognitive-training
#17
Francisco J Román, Yasser Iturria-Medina, Kenia Martínez, Sherif Karama, Miguel Burgaleta, Alan C Evans, Susanne M Jaeggi, Roberto Colom
The structural connectome provides relevant information about experience and training-related changes in the brain. Here, we used network-based statistics (NBS) and graph theoretical analyses to study structural changes in the brain as a function of cognitive training. Fifty-six young women were divided in two groups (experimental and control). We assessed their cognitive function before and after completing a working memory intervention using a comprehensive battery that included fluid and crystallized abilities, working memory and attention control, and we also obtained structural MRI images...
March 18, 2017: Neurobiology of Learning and Memory
https://www.readbyqxmd.com/read/28293468/a-method-for-independent-component-graph-analysis-of-resting-state-fmri
#18
Demetrius Ribeiro de Paula, Erik Ziegler, Pubuditha M Abeyasinghe, Tushar K Das, Carlo Cavaliere, Marco Aiello, Lizette Heine, Carol di Perri, Athena Demertzi, Quentin Noirhomme, Vanessa Charland-Verville, Audrey Vanhaudenhuyse, Johan Stender, Francisco Gomez, Jean-Flory L Tshibanda, Steven Laureys, Adrian M Owen, Andrea Soddu
INTRODUCTION: Independent component analysis (ICA) has been extensively used for reducing task-free BOLD fMRI recordings into spatial maps and their associated time-courses. The spatially identified independent components can be considered as intrinsic connectivity networks (ICNs) of non-contiguous regions. To date, the spatial patterns of the networks have been analyzed with techniques developed for volumetric data. OBJECTIVE: Here, we detail a graph building technique that allows these ICNs to be analyzed with graph theory...
March 2017: Brain and Behavior
https://www.readbyqxmd.com/read/28273767/impairment-of-social-cognition-in-multiple-sclerosis-amygdala-atrophy-is-the-main-predictor
#19
Sonia Batista, Otília C d'Almeida, Ana Afonso, Sandra Freitas, Carmo Macário, Lívia Sousa, Miguel Castelo-Branco, Isabel Santana, Luís Cunha
BACKGROUND: Patients with multiple sclerosis (MS) frequently reveal social behavior disturbance. Nevertheless, little is known regarding the impact of MS on social cognition, particularly theory of mind (ToM), and its neural basis. OBJECTIVES: To explore how ToM is affected in MS and its neural correlates. METHODS: Enrolled 60 consecutive MS patients and 60 healthy controls (HC) matched on age, sex, and education. Participants underwent ToM testing (Eyes Test, Videos Test) and 3 T brain magnetic resonance imaging (MRI)...
December 1, 2016: Multiple Sclerosis: Clinical and Laboratory Research
https://www.readbyqxmd.com/read/28268525/estimating-multimodal-brain-connectivity-in-multiple-sclerosis-an-exploratory-factor-analysis
#20
Matteo Mancini, Giovanni Giulietti, Barbara Spano, Marco Bozzali, Mara Cercignani, Silvia Conforto
Graph-theoretical approaches have become a popular way to model brain data collected using magnetic resonance imaging (MRI), both from the structural and the functional perspectives. In structural networks, tract-based mapping allows to model different aspects of brain structures by means of the specific characteristics of the different MRI modalities. However, there has been little effort to join the information carried by each modality and to understand what level of common variance is shown in these data...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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