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BOLD fMRI

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https://www.readbyqxmd.com/read/28730273/glucose-as-a-stimulation-agent-in-the-bold-functional-magnetic-resonance-imaging-for-liver-cirrhosis-and-hepatocellular-carcinoma-a-feasibility-study
#1
Fang Yuan, Bin Song, Zixing Huang, Xijiao Liu, Chunchao Xia
PURPOSE: To explore the role of glucose as a stimulation agent in the blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) for liver cirrhosis and hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty HCC patients with cirrhosis and 10 healthy volunteers were recruited. BOLD fMRI was performed for all participants prior to and 30 min after oral administration of glucose to measure the T2* values of normal liver parenchyma, HCC liver parenchyma, HCC center, and HCC edge...
July 20, 2017: Abdominal Radiology
https://www.readbyqxmd.com/read/28729926/coherence-of-bold-signal-and-electrical-activity-in-the-human-brain-during-deep-sevoflurane-anesthesia
#2
Daniel Golkowski, Andreas Ranft, Tobias Kiel, Valentin Riedl, Philipp Kohl, Guido Rohrer, Joachim Pientka, Sebastian Berger, Christine Preibisch, Claus Zimmer, George A Mashour, Gerhard Schneider, Eberhard F Kochs, Rüdiger Ilg, Denis Jordan
INTRODUCTION: Changes in neural activity induce changes in functional magnetic resonance (fMRI) blood oxygenation level dependent (BOLD) signal. Commonly, increases in BOLD signal are ascribed to cellular excitation. OBJECTIVE: The relationship between electrical activity and BOLD signal in the human brain was probed on the basis of burst suppression EEG. This condition includes two distinct states of high and low electrical activity. METHODS: Resting-state simultaneous EEG and BOLD measurements were acquired during deep sevoflurane anesthesia with burst suppression EEG in nineteen healthy volunteers...
July 2017: Brain and Behavior
https://www.readbyqxmd.com/read/28729830/resting-state-fluctuations-of-eeg-sensorimotor-rhythm-reflect-bold-activities-in-the-pericentral-areas-a-simultaneous-eeg-fmri-study
#3
Shohei Tsuchimoto, Shuka Shibusawa, Nobuaki Mizuguchi, Kenji Kato, Hiroki Ebata, Meigen Liu, Takashi Hanakawa, Junichi Ushiba
Blockade of the scalp electroencephalographic (EEG) sensorimotor rhythm (SMR) is a well-known phenomenon following attempted or executed motor functions. Such a frequency-specific power attenuation of the SMR occurs in the alpha and beta frequency bands and is spatially registered at primary somatosensory and motor cortices. Here, we hypothesized that resting-state fluctuations of the SMR in the alpha and beta frequency bands also covary with resting-state sensorimotor cortical activity, without involving task-related neural dynamics...
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/28729160/echo-time-dependence-of-the-bold-response-transients-a-window-into-brain-functional-physiology
#4
Martin Havlicek, Dimo Ivanov, Benedikt A Poser, Kamil Uludag
The blood oxygenation level-dependent (BOLD) fMRI response to neuronal activation results from a complex interplay of induced metabolic and vascular changes. Thus, its transients, such as initial overshoot and post-stimulus undershoot, provide a window into the dynamic relationships of the underlying physiological variables. In this study, we propose multi-echo fMRI as a tool to investigate the physiological underpinnings of the BOLD signal, in particular, and brain functional physiology, in general. In the human visual cortex at 3 T, we observed that the BOLD response is nonlinearly dependent on echo-time (TE) and the amount of nonlinearity varies during the entire time-course...
July 17, 2017: NeuroImage
https://www.readbyqxmd.com/read/28729016/learning-based-structurally-guided-construction-of-resting-state-functional-correlation-tensors
#5
Lichi Zhang, Han Zhang, Xiaobo Chen, Qian Wang, Pew-Thian Yap, Dinggang Shen
Functional magnetic resonance imaging (fMRI) measures changes in blood-oxygenation-level-dependent (BOLD) signals to detect brain activities. It has been recently reported that the spatial correlation patterns of resting-state BOLD signals in the white matter (WM) also give WM information often measured by diffusion tensor imaging (DTI). These correlation patterns can be captured using functional correlation tensor (FCT), which is analogous to the diffusion tensor (DT) obtained from DTI. In this paper, we propose a noise-robust FCT method aiming at further improving its quality, and making it eligible for further neuroscience study...
July 17, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28727850/hybrid-cubature-kalman-filtering-for-identifying-nonlinear-models-from-sampled-recording-estimation-of-neuronal-dynamics
#6
Mahmoud K Madi, Fadi N Karameh
Kalman filtering methods have long been regarded as efficient adaptive Bayesian techniques for estimating hidden states in models of linear dynamical systems under Gaussian uncertainty. Recent advents of the Cubature Kalman filter (CKF) have extended this efficient estimation property to nonlinear systems, and also to hybrid nonlinear problems where by the processes are continuous and the observations are discrete (continuous-discrete CD-CKF). Employing CKF techniques, therefore, carries high promise for modeling many biological phenomena where the underlying processes exhibit inherently nonlinear, continuous, and noisy dynamics and the associated measurements are uncertain and time-sampled...
2017: PloS One
https://www.readbyqxmd.com/read/28725547/spatial-working-memory-in-neurofibromatosis-1-altered-neural-activity-and-functional-connectivity
#7
Amira F A Ibrahim, Caroline A Montojo, Kristen M Haut, Katherine H Karlsgodt, Laura Hansen, Eliza Congdon, Tena Rosser, Robert M Bilder, Alcino J Silva, Carrie E Bearden
BACKGROUND: Neurofibromatosis Type 1 (NF1) is a genetic disorder that disrupts central nervous system development and neuronal function. Cognitively, NF1 is characterized by difficulties with executive control and visuospatial abilities. Little is known about the neural substrates underlying these deficits. The current study utilized Blood-Oxygen-Level-Dependent (BOLD) functional MRI (fMRI) to explore the neural correlates of spatial working memory (WM) deficits in patients with NF1. METHODS: BOLD images were acquired from 23 adults with NF1 (age M = 32...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28712063/resisting-sleep-pressure-impact-on-resting-state-functional-network-connectivity
#8
Laura Tüshaus, Joshua Henk Balsters, Anthony Schläpfer, Daniel Brandeis, Ruth O'Gorman Tuura, Peter Achermann
In today's 24/7 society, sleep restriction is a common phenomenon which leads to increased levels of sleep pressure in daily life. However, the magnitude and extent of impairment of brain functioning due to increased sleep pressure is still not completely understood. Resting state network (RSN) analyses have become increasingly popular because they allow us to investigate brain activity patterns in the absence of a specific task and to identify changes under different levels of vigilance (e.g. due to increased sleep pressure)...
July 15, 2017: Brain Topography
https://www.readbyqxmd.com/read/28711813/multi-site-exploration-of-sex-differences-in-brain-reactivity-to-smoking-cues-consensus-across-sites-and-methodologies
#9
Kelly M Dumais, Teresa R Franklin, Kanchana Jagannathan, Nathan Hager, Michael Gawrysiak, Jennifer Betts, Stacey Farmer, Emily Guthier, Heather Pater, Amy C Janes, Reagan R Wetherill
BACKGROUND: Biological sex influences cigarette smoking behavior. More men than women smoke, but women have a harder time quitting. Sex differences in smoking cue (SC) reactivity may underlie such behavioral differences. However, the influence of sex on brain reactivity to SCs has yielded inconsistent findings suggesting the need for continued study. Here, we investigated the effect of sex on SC reactivity across two sites using different imaging modalities and SC stimulus types. METHODS: Pseudo-continuous arterial spin-labeled (pCASL) perfusion functional magnetic resonance imaging (fMRI) was used to assess brain responses to SC versus non-SC videos in 40 smokers (23 females) at the University of Pennsylvania...
July 8, 2017: Drug and Alcohol Dependence
https://www.readbyqxmd.com/read/28701940/reduced-pain-sensation-and-reduced-bold-signal-in-parietofrontal-networks-during-religious-prayer
#10
Else-Marie Elmholdt, Joshua Skewes, Martin Dietz, Arne Møller, Martin S Jensen, Andreas Roepstorff, Katja Wiech, Troels S Jensen
Previous studies suggest that religious prayer can alter the experience of pain via expectation mechanisms. While brain processes related to other types of top-down modulation of pain have been studied extensively, no research has been conducted on the potential effects of active religious coping. Here, we aimed at investigating the neural mechanisms during pain modulation by prayer and their dependency on the opioidergic system. Twenty-eight devout Protestants performed religious prayer and a secular contrast prayer during painful electrical stimulation in two fMRI sessions...
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/28699704/aberrant-blood-oxygen-level-dependent-signal-oscillations-across-frequency-bands-characterize-the-alcoholic-brain
#11
Jui-Yang Hong, Eva M Müller-Oehring, Adolf Pfefferbaum, Edith V Sullivan, Dongjin Kwon, Tilman Schulte
Chronic alcoholism is associated with widespread regional differences from controls in brain activity and connectivity dynamics measured by blood-oxygen-level-dependent (BOLD) signals. Identification of alcoholism-related neurofunctional power dynamics using functional magnetic resonance imaging (fMRI) that relate to cognition and behavior may serve as biomarkers of alcoholism. Previously, resting-state fMRI studies examined BOLD signals at a single low-frequency (LF) bandwidth. BOLD signals, however, oscillate systematically at different frequencies and are organized in a resting brain where LF oscillation facilitates long-distance communication between regions across cortical regions, whereas high-frequency (HF) oscillation occurs in closely localized, subcortical areas...
July 12, 2017: Addiction Biology
https://www.readbyqxmd.com/read/28698012/the-relation-between-craving-and-binge-eating-integrating-neuroimaging-and-ecological-momentary-assessment
#12
Joseph A Wonderlich, Lauren E Breithaupt, Ross D Crosby, James C Thompson, Scott G Engel, Sarah Fischer
The role of craving in binge eating characteristic of bulimia nervosa (BN) is inconclusive. A network of regions associated with cue reactivity to food and substances has been identified, comprised of the amygdala, orbitofrontal cortex, insula, and striatum. The goal of this study was to examine individual differences in BOLD response in this appetitive network as moderators of the relationship between craving and binging in the natural environment in women with BN. Women with BN (N = 16) completed a baseline measure of craving and a fMRI scan, where they viewed neutral cues and food cues...
July 8, 2017: Appetite
https://www.readbyqxmd.com/read/28695791/lutein-and-zeaxanthin-influence-brain-function-in-older-adults-a-randomized-controlled-trial
#13
Cutter A Lindbergh, Lisa M Renzi-Hammond, Billy R Hammond, Douglas P Terry, Catherine M Mewborn, Antonio N Puente, L Stephen Miller
OBJECTIVES: The present study constitutes the first randomized controlled trial to investigate the relation of lutein (L) and zeaxanthin (Z) to brain function using functional magnetic resonance imaging (fMRI). It was hypothesized that L and Z supplementation in older adults would enhance neural efficiency (i.e., reduce activation) and cognitive performance on a verbal learning task relative to placebo. METHODS: A total of 44 community-dwelling older adults (mean age=72 years) were randomly assigned to receive either placebo or L+Z supplementation (12 mg/daily) for 1 year...
July 11, 2017: Journal of the International Neuropsychological Society: JINS
https://www.readbyqxmd.com/read/28687521/simultaneous-gcamp6-based-fiber-photometry-and-fmri-in-rats
#14
Zhifeng Liang, Yuncong Ma, Glenn D R Watson, Nanyin Zhang
BACKGROUND: Understanding the relationship between neural and vascular signals is essential for interpretation of functional MRI (fMRI) results with respect to underlying neuronal activity. Simultaneously measuring neural activity using electrophysiology with fMRI has been highly valuable in elucidating the neural basis of the blood oxygenation-level dependent (BOLD) signal. However, this approach is also technically challenging due to the electromagnetic interference that is observed in electrophysiological recordings during MRI scanning...
July 4, 2017: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/28687518/neural-inhibition-can-explain-negative-bold-responses-a-mechanistic-modelling-and-fmri-study
#15
S Sten, K Lundengård, S T Witt, G Cedersund, F Elinder, M Engström
Functional magnetic resonance imaging (fMRI) of hemodynamic changes captured in the blood oxygen level-dependent (BOLD) response contains information of brain activity. The BOLD response is the result of a complex neurovascular coupling and comes in at least two fundamentally different forms: a positive and a negative deflection. Because of the complexity of the signaling, mathematical modelling can provide vital help in the data analysis. For the positive BOLD response, there are plenty of mathematical models, both physiological and phenomenological...
July 4, 2017: NeuroImage
https://www.readbyqxmd.com/read/28687517/comparing-test-retest-reliability-of-dynamic-functional-connectivity-methods
#16
Ann S Choe, Mary Beth Nebel, Anita D Barber, Jessica R Cohen, Yuting Xu, James J Pekar, Brian Caffo, Martin A Lindquist
Due to the dynamic, condition-dependent nature of brain activity, interest in estimating rapid functional connectivity (FC) changes that occur during resting-state functional magnetic resonance imaging (rs-fMRI) has recently soared. However, studying dynamic FC is methodologically challenging, due to the low signal-to-noise ratio of the blood oxygen level dependent (BOLD) signal in fMRI and the massive number of data points generated during the analysis. Thus, it is important to establish methods and summary measures that maximize reliability and the utility of dynamic FC to provide insight into brain function...
July 5, 2017: NeuroImage
https://www.readbyqxmd.com/read/28686788/influence-of-physiological-noise-on-accelerated-2d-and-3d-resting-state-functional-mri-data-at-7%C3%A2-t
#17
Olivier Reynaud, João Jorge, Rolf Gruetter, José P Marques, Wietske van der Zwaag
PURPOSE: Physiological noise often dominates the blood-oxygen level-dependent (BOLD) signal fluctuations in high-field functional MRI (fMRI) data. Therefore, to optimize fMRI protocols, it becomes crucial to investigate how physiological signal fluctuations impact various acquisition and reconstruction schemes at different acquisition speeds. In particular, further differences can arise between 2D and 3D fMRI acquisitions due to different encoding strategies, thereby impacting fMRI sensitivity in potentially significant ways...
July 7, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28686137/using-a-large-scale-neural-model-of-cortical-object-processing-to-investigate-the-neural-substrate-for-managing-multiple-items-in-short-term-memory
#18
Qin Liu, Antonio Ulloa, Barry Horwitz
Many cognitive and computational models have been proposed to help understand working memory. In this article, we present a simulation study of cortical processing of visual objects during several working memory tasks using an extended version of a previously constructed large-scale neural model [Tagamets, M. A., & Horwitz, B. Integrating electrophysiological and anatomical experimental data to create a large-scale model that simulates a delayed match-to-sample human brain imaging study. Cerebral Cortex, 8, 310-320, 1998]...
July 7, 2017: Journal of Cognitive Neuroscience
https://www.readbyqxmd.com/read/28686073/effect-of-hypoxia-on-bold-fmri-response-and-total-cerebral-blood-flow-in-migraine-with-aura-patients
#19
Nanna Arngrim, Anders Hougaard, Henrik W Schytz, Mark B Vestergaard, Josefine Britze, Faisal Mohammad Amin, Karsten S Olsen, Henrik Bw Larsson, Jes Olesen, Messoud Ashina
Experimentally induced hypoxia triggers migraine and aura attacks in patients suffering from migraine with aura (MA). We investigated the blood oxygenation level-dependent (BOLD) signal response to visual stimulation during hypoxia in MA patients and healthy volunteers. In a randomized double-blind crossover study design, 15 MA patients were allocated to 180 min of normobaric poikilocapnic hypoxia (capillary oxygen saturation 70-75%) or sham (normoxia) on two separate days and 14 healthy volunteers were exposed to hypoxia...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28685319/workflow-for-visualization-of-neuroimaging-data-with-an-augmented-reality-device
#20
Christof Karmonik, Timothy B Boone, Rose Khavari
Commercial availability of three-dimensional (3D) augmented reality (AR) devices has increased interest in using this novel technology for visualizing neuroimaging data. Here, a technical workflow and algorithm for importing 3D surface-based segmentations derived from magnetic resonance imaging data into a head-mounted AR device is presented and illustrated on selected examples: the pial cortical surface of the human brain, fMRI BOLD maps, reconstructed white matter tracts, and a brain network of functional connectivity...
July 6, 2017: Journal of Digital Imaging: the Official Journal of the Society for Computer Applications in Radiology
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