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BOLD fMRI

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https://www.readbyqxmd.com/read/28325028/tracking-intrinsic-connectivity-brain-network-features-during-successive-pseudo-resting-states-and-interoceptive-task-fmri
#1
Behnaz Jarrahi, Dante Mantini
Advanced multivariate analyses of functional magnetic resonance imaging (fMRI) data based on blood oxygen level-dependent (BOLD) contras have revealed that the human brain organizes its activities into multiple intrinsic connectivity networks (ICNs). Several fMRI studies have evaluated the modulations of these networks during different cognitive or emotional tasks using blind source separation techniques particularly the independent component analysis (ICA). In this exploratory study, we applied ICA methodology to examine ICN modulations under different interoceptive conditions...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28325027/identifying-the-effects-of-visceral-interoception-on-human-brain-connectome-a-multivariate-analysis-of-covariance-of-fmri-data
#2
Behnaz Jarrahi, Dante Mantini
Sources of variations in the neural circuitry of the human brain and interrelationship between intrinsic connectivity networks (ICNs) are still a matter of debate and ongoing research. Here, we applied a multivariate analysis of covariance (MANCOVA) based on high-dimensional independent component analysis (ICA) to identify the effects of interoception and related variables on human brain connectome. Fifteen healthy right-handed subjects (all females, age range 21 - 48 years; mean age = 30.3, SD = 8.7 years) underwent a blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) that included continuous intravesical saline infusion and drainage...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28323821/comparing-resting-state-fmri-de-noising-approaches-using-multi-and-single-echo-acquisitions
#3
Ottavia Dipasquale, Arjun Sethi, Maria Marcella Laganà, Francesca Baglio, Giuseppe Baselli, Prantik Kundu, Neil A Harrison, Mara Cercignani
Artifact removal in resting state fMRI (rfMRI) data remains a serious challenge, with even subtle head motion undermining reliability and reproducibility. Here we compared some of the most popular single-echo de-noising methods-regression of Motion parameters, White matter and Cerebrospinal fluid signals (MWC method), FMRIB's ICA-based X-noiseifier (FIX) and ICA-based Automatic Removal Of Motion Artifacts (ICA-AROMA)-with a multi-echo approach (ME-ICA) that exploits the linear dependency of BOLD on the echo time...
2017: PloS One
https://www.readbyqxmd.com/read/28323165/on-the-importance-of-modeling-fmri-transients-when-estimating-effective-connectivity-a-dynamic-causal-modeling-study-using-asl-data
#4
Martin Havlicek, Alard Roebroeck, Karl J Friston, Anna Gardumi, Dimo Ivanov, Kamil Uludag
Effective connectivity is commonly assessed using blood oxygenation level-dependent (BOLD) signals. In (Havlicek et al., 2015), we presented a novel, physiologically informed dynamic causal model (P-DCM) that extends current generative models. We demonstrated the improvements afforded by P-DCM in terms of the ability to model commonly observed neuronal and vascular transients in single regions. Here, we assess the ability of the novel and previous DCM variants to estimate effective connectivity among a network of five ROIs driven by a visuo-motor task...
March 16, 2017: NeuroImage
https://www.readbyqxmd.com/read/28322859/decoding-the-encoding-of-functional-brain-networks-an-fmri-classification-comparison-of-non-negative-matrix-factorization-nmf-independent-component-analysis-ica-and-sparse-coding-algorithms
#5
Jianwen Xie, Pamela K Douglas, Ying Nian Wu, Arthur L Brody, Ariana E Anderson
BACKGROUND: Brain networks in fMRI are typically identified using spatial independent component analysis (ICA), yet other mathematical constraints provide alternate biologically-plausible frameworks for generating brain networks. Non-negative Matrix Factorization (NMF) would suppress negative BOLD signal by enforcing positivity. Spatial sparse coding algorithms (L1 Regularized Learning and K-SVD) would impose local specialization and a discouragement of multitasking, where the total observed activity in a single voxel originates from a restricted number of possible brain networks...
March 17, 2017: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/28320141/functional-magnetic-resonance-imaging-responses-in-cadasil
#6
Ikreet Cheema, Aaron R Switzer, Cheryl R McCreary, Michael D Hill, Richard Frayne, Bradley G Goodyear, Eric E Smith
OBJECTIVES: The magnitude of the blood oxygen dependent level (BOLD) functional MRI (fMRI) response to visual stimulation is reduced in the small vessel disease cerebral amyloid angiopathy (CAA), reflecting impaired vascular reactivity. We determined whether BOLD responses were reduced in another small vessel disease, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). METHODS: BOLD fMRI data were collected using a visual stimulus (contrast-reversing checkerboard) and motor task (finger-tapping)...
April 15, 2017: Journal of the Neurological Sciences
https://www.readbyqxmd.com/read/28316564/functional-circuitry-effect-of-ventral-tegmental-area-deep-brain-stimulation-imaging-and-neurochemical-evidence-of-mesocortical-and-mesolimbic-pathway-modulation
#7
Megan L Settell, Paola Testini, Shinho Cho, Jannifer H Lee, Charles D Blaha, Hang J Jo, Kendall H Lee, Hoon-Ki Min
Background: The ventral tegmental area (VTA), containing mesolimbic and mesocortical dopaminergic neurons, is implicated in processes involving reward, addiction, reinforcement, and learning, which are associated with a variety of neuropsychiatric disorders. Electrical stimulation of the VTA or the medial forebrain bundle and its projection target the nucleus accumbens (NAc) is reported to improve depressive symptoms in patients affected by severe, treatment-resistant major depressive disorder (MDD) and depressive-like symptoms in animal models of depression...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28298891/white-matter-deterioration-may-foreshadow-impairment-of-emotional-valence-determination-in-early-stage-dementia-of-the-alzheimer-type
#8
Ravi Rajmohan, Ronald C Anderson, Dan Fang, Austin G Meyer, Pavis Laengvejkal, Parunyou Julayanont, Greg Hannabas, Kitten Linton, John Culberson, Hafiz M R Khan, John De Toledo, P Hemachandra Reddy, Michael O'Boyle
In Alzheimer Disease (AD), non-verbal skills often remain intact for far longer than verbally mediated processes. Four (1 female, 3 males) participants with early-stage Clinically Diagnosed Dementia of the Alzheimer Type (CDDAT) and eight neurotypicals (NTs; 4 females, 4 males) completed the emotional valence determination test (EVDT) while undergoing BOLD functional magnetic resonance imaging (fMRI). We expected CDDAT participants to perform just as well as NTs on the EVDT, and to display increased activity within the bilateral amygdala and right anterior cingulate cortex (r-ACC)...
2017: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/28295824/wavelet-entropy-of-bold-time-series-an-application-to-rolandic-epilepsy
#9
Lalit Gupta, Jacobus F A Jansen, Paul A M Hofman, René M H Besseling, Anton J A de Louw, Albert P Aldenkamp, Walter H Backes
PURPOSE: To assess the wavelet entropy for the characterization of intrinsic aberrant temporal irregularities in the time series of resting-state blood-oxygen-level-dependent (BOLD) signal fluctuations. Further, to evaluate the temporal irregularities (disorder/order) on a voxel-by-voxel basis in the brains of children with Rolandic epilepsy. MATERIALS AND METHODS: The BOLD time series was decomposed using the discrete wavelet transform and the wavelet entropy was calculated...
March 11, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28294714/where-is-the-beat-the-neural-correlates-of-lexical-stress-and-rhythmical-well-formedness-in-auditory-story-comprehension
#10
Katerina D Kandylaki, Karen Henrich, Arne Nagels, Tilo Kircher, Ulrike Domahs, Matthias Schlesewsky, Ina Bornkessel-Schlesewsky, Richard Wiese
While processing continuous speech, humans use beat perception to correctly identify word boundaries. The beats of language are stress patterns that are created by combining lexical (word-specific) stress patterns and the rhythm of a specific language. Sometimes, the lexical stress pattern needs to be altered to obey the rhythm of the language. This study investigated this interplay of lexical stress patterns and rhythmical well-formedness in natural speech with fMRI. Previous electrophysiological studies on cases in which a regular lexical stress pattern may be altered to obtain rhythmical well-formedness showed that even subtle rhythmic deviations are detected by the brain if attention is directed toward prosody...
March 15, 2017: Journal of Cognitive Neuroscience
https://www.readbyqxmd.com/read/28294187/neurophysiological-and-bold-signal-uncoupling-of-giant-somatosensory-evoked-potentials-in-progressive-myoclonic-epilepsy-a-case-series-study
#11
Silvia F Storti, Alessandra Del Felice, Laura Canafoglia, Emanuela Formaggio, Francesco Brigo, Franco Alessandrini, Luigi G Bongiovanni, Gloria Menegaz, Paolo Manganotti
In progressive myoclonic epilepsy (PME), a rare epileptic syndrome caused by a variety of genetic disorders, the combination of peripheral stimulation and functional magnetic resonance imaging (fMRI) can shed light on the mechanisms underlying cortical dysfunction. The aim of the study is to investigate sensorimotor network modifications in PME by assessing the relationship between neurophysiological findings and blood oxygen level dependent (BOLD) activation. Somatosensory-evoked potential (SSEP) obtained briefly before fMRI and BOLD activation during median-nerve electrical stimulation were recorded in four subjects with typical PME phenotype and compared with normative data...
March 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28293468/a-method-for-independent-component-graph-analysis-of-resting-state-fmri
#12
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/28286317/7t-fmri-faster-temporal-resolution-yields-optimal-bold-sensitivity-for-functional-network-imaging-specifically-at-high-spatial-resolution
#13
Peter E Yoo, Sam E John, Shawna Farquharson, Jon O Cleary, Yan T Wong, Amanda Ng, Claire Mulcahy, David B Grayden, Roger J Ordidge, Nicholas L Opie, Terence J O'Brien, Thomas J Oxley, Bradford A Moffat
Recent developments in accelerated imaging methods allow faster acquisition of high spatial resolution images. This could improve the applications of functional magnetic resonance imaging at 7 T (7T-fMRI), such as neurosurgical planning and Brain Computer Interfaces (BCIs). However, increasing the spatial and temporal resolution will both lead to signal-to-noise ratio (SNR) losses due to decreased signal intensity and T1-relaxation effect, respectively. This could potentially offset the SNR efficiency gains made with increasing temporal resolution...
March 7, 2017: NeuroImage
https://www.readbyqxmd.com/read/28277456/resting-state-bold-mri-for-perfusion-and-ischemia
#14
Hannes Kroll, Greg Zaharchuk, Thomas Christen, Jeremy J Heit, Michael Iv
Advanced imaging techniques including computed tomography (CT) angiography, CT perfusion, magnetic resonance (MR) angiography, MR with diffusion- and perfusion-weighted imaging, and, more recently, resting-state BOLD (Blood Oxygen Level Dependent) functional MRI (rs-fMRI) are increasingly used to evaluate patients with acute ischemic stroke. Advanced imaging allows for identification of patients with ischemic stroke and determination of the size of infarcted and potentially salvageable tissue, all of which yield crucial information for proper stroke management...
March 8, 2017: Topics in Magnetic Resonance Imaging: TMRI
https://www.readbyqxmd.com/read/28274833/investigating-the-spatiotemporal-characteristics-of-the-deoxyhemoglobin-related-and-deoxyhemoglobin-unrelated-functional-hemodynamic-response-across-cortical-layers-in-awake-marmosets
#15
Cecil Chern-Chyi Yen, Daniel Papoti, Afonso C Silva
Blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) has become a major tool to map neural activity. However, the spatiotemporal characteristics of the BOLD functional hemodynamic response across the cortical layers remain poorly understood. While human fMRI studies suffer from low spatiotemporal resolution, the use of anesthesia in animal models introduces confounding factors. Additionally, inflow contributions to the fMRI signal become non-negligible when short repetition times (TRs) are used...
March 6, 2017: NeuroImage
https://www.readbyqxmd.com/read/28273110/transient-human-auditory-cortex-activation-during-volitional-attention-shifting
#16
Christian Harm Uhlig, Alexander Gutschalk
While strong activation of auditory cortex is generally found for exogenous orienting of attention, endogenous, intra-modal shifting of auditory attention has not yet been demonstrated to evoke transient activation of the auditory cortex. Here, we used fMRI to test if endogenous shifting of attention is also associated with transient activation of the auditory cortex. In contrast to previous studies, attention shifts were completely self-initiated and not cued by transient auditory or visual stimuli. Stimuli were two dichotic, continuous streams of tones, whose perceptual grouping was not ambiguous...
2017: PloS One
https://www.readbyqxmd.com/read/28271954/mathematical-analysis-of-the-influence-of-brain-metabolism-on-the-bold-signal-in-alzheimer-s-disease
#17
Felix Winter, Catrin Bludszuweit-Philipp, Olaf Wolkenhauer
Blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI) is a standard clinical tool for the detection of brain activation. In Alzheimer's disease (AD), task-related and resting state fMRI have been used to detect brain dysfunction. It has been shown that the shape of the BOLD response is affected in early AD. To correctly interpret these changes, the mechanisms responsible for the observed behaviour need to be known. The parameters of the canonical hemodynamic response function (HRF) commonly used in the analysis of fMRI data have no direct biological interpretation and cannot be used to answer this question...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28270764/does-chronic-tinnitus-alter-the-emotional-response-function-of-the-amygdala-a-sound-evoked-fmri-study
#18
Jeff E Davies, Phillip E Gander, Deborah A Hall
Tinnitus is often associated with strong negative thoughts and emotions which can contribute to a distressing and chronic long-term condition. The amygdala, the "feeling and reacting" part of the brain, may play a key role in this process. Although implicated in several theoretical models of tinnitus, quantification of activity in the human amygdala has only been made possible more recently through neuroimaging methods such as functional magnetic resonance imaging (fMRI) but benefits from modified scanning parameters using a double-echo acquisition for improved BOLD sensitivity...
2017: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/28269516/randomness-in-resting-state-functional-connectivity-matrices
#19
Victor M Vergara, Vince Calhoun
Separate brain regions exhibit synchronous intrinsic activity used to assess connectivity patterns known to appear among brain areas. Connectivity is evaluated from functional magnetic resonance imaging (fMRI) measuring the blood oxygen level dependent signal (BOLD) signal. Extensive research has revealed a distinctive pattern of connectivity among brain areas that can be visualized through a functional connectivity matrix (FCM) matrix. As in any measurement, BOLD signals are subject to contamination from noise and nuisances unrelated to brain's intrinsic activity...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28269497/reconstructing-multivariate-causal-structure-between-functional-brain-networks-through-a-laguerre-volterra-based-granger-causality-approach
#20
Andrea Duggento, Gaetano Valenza, Luca Passamonti, Maria Guerrisi, Riccardo Barbieri, Nicola Toschi
Classical multivariate approaches based on Granger causality (GC) which estimate functional connectivity in the brain are almost exclusively based on autoregressive models. Nevertheless, information available from past samples is limited due to both signal autocorrelation and necessarily low model orders. Consequently, multiple time-scales interactions are usually unaccounted for. To overcome these limitations, in this study we propose the use of discrete-time orthogonal Laguerre basis functions within a Wiener-Volterra decomposition of the BOLD signals to perform effective GC assessments of brain functional connectivity...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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