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https://www.readbyqxmd.com/read/28333589/a-unified-theory-of-neuro-mri-data-shows-scale-free-nature-of-connectivity-modes
#1
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
#2
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...
March 23, 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
#3
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 16, 2017: Neurobiology of Learning and Memory
https://www.readbyqxmd.com/read/28293468/a-method-for-independent-component-graph-analysis-of-resting-state-fmri
#4
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
#5
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
#6
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
https://www.readbyqxmd.com/read/28266518/altered-topological-properties-of-brain-networks-in-social-anxiety-disorder-a-resting-state-functional-mri-study
#7
Hongru Zhu, Changjian Qiu, Yajing Meng, Minlan Yuan, Yan Zhang, Zhengjia Ren, Yuchen Li, Xiaoqi Huang, Qiyong Gong, Su Lui, Wei Zhang
Recent studies involving connectome analysis including graph theory have yielded potential biomarkers for mental disorders. In this study, we aimed to investigate the differences of resting-state network between patients with social anxiety disorder (SAD) and healthy controls (HCs), as well as to distinguish between individual subjects using topological properties. In total, 42 SAD patients and the same number of HCs underwent resting functional MRI, and the topological organization of the whole-brain functional network was calculated using graph theory...
March 7, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28266002/voxel-based-mapping-of-grey-matter-volume-and-glucose-metabolism-profiles-in-amyotrophic-lateral-sclerosis
#8
M-S Buhour, F Doidy, A Mondou, A Pélerin, L Carluer, F Eustache, F Viader, B Desgranges
BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a rapidly progressive disease of the nervous system involving both upper and lower motor neurons. The patterns of structural and metabolic brain alterations are still unclear. Several studies using anatomical MRI yielded a number of discrepancies in their results, and a few PET studies investigated the effect of ALS on cerebral glucose metabolism. The aim of this study was threefold: to highlight the patterns of grey matter (GM) atrophy, hypometabolism and hypermetabolism in patients with ALS, then to understand the neurobehavioral significance of hypermetabolism and, finally, to investigate the regional differences between the morphologic and functional changes in ALS patients, using a specially designed voxel-based method...
December 2017: EJNMMI Research
https://www.readbyqxmd.com/read/28249008/characterization-of-the-resting-state-brain-network-topology-in-the-6-hydroxydopamine-rat-model-of-parkinson-s-disease
#9
Robert Westphal, Camilla Simmons, Michel B Mesquita, Tobias C Wood, Steve C R Williams, Anthony C Vernon, Diana Cash
Resting-state functional MRI (rsfMRI) is an imaging technology that has recently gained attention for its ability to detect disruptions in functional brain networks in humans, including in patients with Parkinson's disease (PD), revealing early and widespread brain network abnormalities. This methodology is now readily applicable to experimental animals offering new possibilities for cross-species translational imaging. In this context, we herein describe the application of rsfMRI to the unilaterally-lesioned 6-hydroxydopamine (6-OHDA) rat, a robust experimental model of the dopamine depletion implicated in PD...
2017: PloS One
https://www.readbyqxmd.com/read/28226699/estimating-multimodal-brain-connectivity-in-multiple-sclerosis-an-exploratory-factor-analysis
#10
Matteo Mancini, Giovanni Giulietti, Barbara Spano, Marco Bozzali, Mara Cercignani, Silvia Conforto, Matteo Mancini, Giovanni Giulietti, Barbara Spano, Marco Bozzali, Mara Cercignani, Silvia Conforto, Giovanni Giulietti, Mara Cercignani, Silvia Conforto, Matteo Mancini, Barbara Spano, Marco Bozzali
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
https://www.readbyqxmd.com/read/28219628/subcortical-brain-volume-differences-in-participants-with-attention-deficit-hyperactivity-disorder-in-children-and-adults-a-cross-sectional-mega-analysis
#11
Martine Hoogman, Janita Bralten, Derrek P Hibar, Maarten Mennes, Marcel P Zwiers, Lizanne S J Schweren, Kimm J E van Hulzen, Sarah E Medland, Elena Shumskaya, Neda Jahanshad, Patrick de Zeeuw, Eszter Szekely, Gustavo Sudre, Thomas Wolfers, Alberdingk M H Onnink, Janneke T Dammers, Jeanette C Mostert, Yolanda Vives-Gilabert, Gregor Kohls, Eileen Oberwelland, Jochen Seitz, Martin Schulte-Rüther, Sara Ambrosino, Alysa E Doyle, Marie F Høvik, Margaretha Dramsdahl, Leanne Tamm, Theo G M van Erp, Anders Dale, Andrew Schork, Annette Conzelmann, Kathrin Zierhut, Ramona Baur, Hazel McCarthy, Yuliya N Yoncheva, Ana Cubillo, Kaylita Chantiluke, Mitul A Mehta, Yannis Paloyelis, Sarah Hohmann, Sarah Baumeister, Ivanei Bramati, Paulo Mattos, Fernanda Tovar-Moll, Pamela Douglas, Tobias Banaschewski, Daniel Brandeis, Jonna Kuntsi, Philip Asherson, Katya Rubia, Clare Kelly, Adriana Di Martino, Michael P Milham, Francisco X Castellanos, Thomas Frodl, Mariam Zentis, Klaus-Peter Lesch, Andreas Reif, Paul Pauli, Terry L Jernigan, Jan Haavik, Kerstin J Plessen, Astri J Lundervold, Kenneth Hugdahl, Larry J Seidman, Joseph Biederman, Nanda Rommelse, Dirk J Heslenfeld, Catharina A Hartman, Pieter J Hoekstra, Jaap Oosterlaan, Georg von Polier, Kerstin Konrad, Oscar Vilarroya, Josep Antoni Ramos-Quiroga, Joan Carles Soliva, Sarah Durston, Jan K Buitelaar, Stephen V Faraone, Philip Shaw, Paul M Thompson, Barbara Franke
BACKGROUND: Neuroimaging studies have shown structural alterations in several brain regions in children and adults with attention deficit hyperactivity disorder (ADHD). Through the formation of the international ENIGMA ADHD Working Group, we aimed to address weaknesses of previous imaging studies and meta-analyses, namely inadequate sample size and methodological heterogeneity. We aimed to investigate whether there are structural differences in children and adults with ADHD compared with those without this diagnosis...
February 16, 2017: Lancet Psychiatry
https://www.readbyqxmd.com/read/28213111/childhood-maltreatment-is-associated-with-alteration-in-global-network-fiber-tract-architecture-independent-of-history-of-depression-and-anxiety
#12
Kyoko Ohashi, Carl M Anderson, Elizabeth A Bolger, Alaptagin Khan, Cynthia E McGreenery, Martin H Teicher
Childhood maltreatment is a major risk factor for psychopathology. It is also associated with alterations in the network architecture of the brain, which we hypothesized may play a significant role in the development of psychopathology. In this study, we analyzed the global network architecture of physically healthy unmedicated 18-25 year old subjects (n=262) using diffusion tensor imaging (DTI) MRI and tractography. Anatomical networks were constructed from fiber streams interconnecting 90 cortical or subcortical regions for subjects with no-to-low (n=122) versus moderate-to-high (n=140) exposure to maltreatment...
February 16, 2017: NeuroImage
https://www.readbyqxmd.com/read/28181217/hypercoagulability-and-migraine
#13
Gretchen E Tietjen, Stuart A Collins
BACKGROUND: A growing body of literature suggests that migraineurs, particularly those with aura, have an increased risk for ischemic stroke, but not via enhanced atherosclerosis. The theory that micro-emboli induced ischemia provokes cortical spreading depression (ie, symptomatic aura) in migraineurs but transient ischemic attacks in others highlights a potential role for hypercoagulability as a link between migraine (with aura) and stroke. AIM: Our objective is to summarize the literature evaluating the association of migraine with various acquired or inheritable thrombophilic states, including those related to elevated estrogen levels, endothelial activation and dysfunction, antiphospholipid antibodies (aPL), deficiency of coagulation inhibitors, and presence of certain genetic polymorphisms...
February 9, 2017: Headache
https://www.readbyqxmd.com/read/28174333/resting-state-network-topology-differentiates-task-signals-across-the-adult-life-span
#14
Micaela Y Chan, Fahd H Alhazmi, Denise C Park, Neil K Savalia, Gagan S Wig
Brain network connectivity differs across individuals. For example, older adults exhibit less segregated resting-state subnetworks relative to younger adults (Chan et al., 2014). It has been hypothesized that individual differences in network connectivity impact the recruitment of brain areas during task execution. While recent studies have described the spatial overlap between resting-state functional correlation (RSFC) subnetworks and task-evoked activity, it is unclear whether individual variations in the connectivity pattern of a brain area (topology) relates to its activity during task execution...
March 8, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28171781/increased-white-matter-radial-diffusivity-is-associated-with-prefrontal-cortical-folding-deficits-in-schizophrenia
#15
C Christoph Schultz, Gerd Wagner, Claudia Schachtzabel, Jürgen R Reichenbach, Ralf G M Schlösser, Heinrich Sauer, Kathrin Koch
The neuronal underpinnings of cortical folding alterations in schizophrenia remain unclear. Theories on the physiological development of cortical folds stress the importance of white matter fibers for this process and disturbances of fiber tracts might be relevant for cortical folding alterations in schizophrenia. Nine-teen patients with schizophrenia and 19 healthy subjects underwent T1-weighted MRI and DTI. Cortical folding was computed using a surface based approach. DTI was analyzed using FSL and SPM 5...
February 4, 2017: Psychiatry Research
https://www.readbyqxmd.com/read/28149924/deformable-image-registration-for-tissues-with-large-displacements
#16
Xishi Huang, Jing Ren, Anwar Abdalbari, Mark Green
Image registration for internal organs and soft tissues is considered extremely challenging due to organ shifts and tissue deformation caused by patients' movements such as respiration and repositioning. In our previous work, we proposed a fast registration method for deformable tissues with small rotations. We extend our method to deformable registration of soft tissues with large displacements. We analyzed the deformation field of the liver by decomposing the deformation into shift, rotation, and pure deformation components and concluded that in many clinical cases, the liver deformation contains large rotations and small deformations...
January 2017: Journal of Medical Imaging
https://www.readbyqxmd.com/read/28129150/the-spurs-algorithm-for-resampling-an-irregularly-sampled-signal-onto-a-cartesian-grid
#17
Amir Kiperwas, Daniel Rosenfeld, Yonina C Eldar
We present an algorithm for resampling a function from its values on a non-Cartesian grid onto a Cartesian grid. This problem arises in many applications such as MRI, CT, radio astronomy and geophysics. Our algorithm, termed SParse Uniform ReSampling (SPURS), employs methods from modern sampling theory to achieve a small approximation error while maintaining low computational cost. The given non-Cartesian samples are projected onto a selected intermediate subspace, spanned by integer translations of a compactly supported kernel function...
November 1, 2016: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28127519/increased-thalamic-centrality-and-putamen-thalamic-connectivity-in-patients-with-parkinsonian-resting-tremor
#18
Quanquan Gu, Hengyi Cao, Min Xuan, Wei Luo, Xiaojun Guan, Jingjing Xu, Peiyu Huang, Minming Zhang, Xiaojun Xu
INTRODUCTION: Evidence has indicated a strong association between hyperactivity in the cerebello-thalamo-motor cortical loop and resting tremor in Parkinson's disease (PD). Within this loop, the thalamus serves as a central hub based on its structural centrality in the generation of resting tremor. To study whether this thalamic abnormality leads to an alteration at the whole-brain level, our study investigated the role of the thalamus in patients with parkinsonian resting tremor in a large-scale brain network context...
January 2017: Brain and Behavior
https://www.readbyqxmd.com/read/28116232/changes-in-functional-organization-and-white-matter-integrity-in-the-connectome-in-parkinson-s-disease
#19
Sule Tinaz, Peter M Lauro, Pritha Ghosh, Codrin Lungu, Silvina G Horovitz
Parkinson's disease (PD) leads to dysfunction in multiple cortico-striatal circuits. The neurodegeneration has also been associated with impaired white matter integrity. This structural and functional "disconnection" in PD needs further characterization. We investigated the structural and functional organization of the PD whole brain connectome consisting of 200 nodes using diffusion tensor imaging and resting-state functional MRI, respectively. Data from 20 non-demented PD patients on dopaminergic medication and 20 matched controls were analyzed using graph theory-based methods...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28113840/a-projection-algorithm-for-gradient-waveforms-design-in-magnetic-resonance-imaging
#20
Nicolas Chauffert, Pierre Weiss, Jonas Kahn, Philippe Ciuciu
Collecting the maximal amount of information in a given scanning time is a major concern in Magnetic Resonance Imaging (MRI) to speed up image acquisition. The hardware constraints (gradient magnitude, slew rate, ...), physical distortions (e.g., off-resonance effects) and sampling theorems (Shannon, compressed sensing) must be taken into account simultaneously, which makes this problem extremely challenging. To date, the main approach to design gradient waveform has consisted of selecting an initial shape (e...
March 21, 2016: IEEE Transactions on Medical Imaging
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