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BOLD Mri

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https://www.readbyqxmd.com/read/28320141/functional-magnetic-resonance-imaging-responses-in-cadasil
#1
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/28293468/a-method-for-independent-component-graph-analysis-of-resting-state-fmri
#2
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/28284801/functional-connectivity-and-activity-of-white-matter-in-somatosensory-pathways-under-tactile-stimulations
#3
Xi Wu, Zhipeng Yang, Stephen K Bailey, Jiliu Zhou, Laurie E Cutting, John C Gore, Zhaohua Ding
Functional MRI has proven to be effective in detecting neural activity in brain cortices on the basis of blood oxygenation level dependent (BOLD) contrast, but has relatively poor sensitivity for detecting neural activity in white matter. To demonstrate that BOLD signals in white matter are detectable and contain information on neural activity, we stimulated the somatosensory system and examined distributions of BOLD signals in related white matter pathways. The temporal correlation profiles and frequency contents of BOLD signals were compared between stimulation and resting conditions, and between relevant white matter fibers and background regions, as well as between left and right side stimulations...
March 8, 2017: NeuroImage
https://www.readbyqxmd.com/read/28277456/resting-state-bold-mri-for-perfusion-and-ischemia
#4
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/28275197/relationship-between-changes-in-the-temporal-dynamics-of-the-blood-oxygen-level-dependent-signal-and-hypoperfusion-in-acute-ischemic-stroke
#5
Ahmed A Khalil, Ann-Christin Ostwaldt, Till Nierhaus, Ramanan Ganeshan, Heinrich J Audebert, Kersten Villringer, Arno Villringer, Jochen B Fiebach
BACKGROUND AND PURPOSE: Changes in the blood-oxygen-level-dependent (BOLD) signal provide a noninvasive measure of blood flow, but a detailed comparison with established perfusion parameters in acute stroke is lacking. We investigated the relationship between BOLD signal temporal delay and dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) in stroke patients. METHODS: In 30 patients with acute (<24 hours) ischemic stroke, we performed Pearson correlation and multiple linear regression between DSC-MRI parameters (time to maximum [Tmax], mean transit time, cerebral blood flow, and cerebral blood volume) and BOLD-based parameters (BOLD delay and coefficient of BOLD variation)...
March 8, 2017: Stroke; a Journal of Cerebral Circulation
https://www.readbyqxmd.com/read/28268667/transcranial-focused-ultrasound-for-bold-fmri-signal-modulation-in-humans
#6
Leo Ai, Jerel K Mueller, Andrea Grant, Yigitcan Eryaman, Wynn Legon
Transcranial focused ultrasound (tFUS) is an emerging form of non-surgical human neuromodulation that confers advantages over existing electro and electromagnetic technologies by providing a superior spatial resolution on the millimeter scale as well as the capability to target sub-cortical structures non-invasively. An examination of the pairing of tFUS and blood oxygen level dependent (BOLD) functional MRI (fMRI) in humans is presented here.
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28265244/contributions-of-eeg-fmri-to-assessing-the-epileptogenicity-of-focal-cortical-dysplasia
#7
Francesca Pittau, Lorenzo Ferri, Firas Fahoum, François Dubeau, Jean Gotman
Purpose: To examine the ability of the BOLD response to EEG spikes to assess the epileptogenicity of the lesion in patients with focal cortical dysplasia (FCD). Method: Patients with focal epilepsy and FCD who underwent 3T EEG-fMRI from 2006 to 2010 were included. Diagnosis of FCD was based on neuroradiology (MRI+), or histopathology in MRI-negative cases (MRI-). Patients underwent 120 min EEG-fMRI recording session. Spikes similar to those recorded outside the scanner were marked in the filtered EEG. The lesion (in MRI+) or the removed cortex (in MRI-) was marked on the anatomical T1 sequence, blindly to the BOLD response, after reviewing the FLAIR images...
2017: Frontiers in Computational Neuroscience
https://www.readbyqxmd.com/read/28260681/the-effect-of-task-difficulty-on-motor-performance-and-frontal-striatal-connectivity-in-cocaine-users
#8
Daniel H Lench, William DeVries, Colleen A Hanlon
BACKGROUND: There is growing recognition that chronic cocaine users have alterations in sensorimotor control that are positively related to low frontal-striatal connectivity within the motor system. These frontal-striatal motor circuits however, are modulated by circuits governing attention, which are also disrupted in cocaine users. This study's aim was to determine if sensorimotor control deficits are positively related to the difficulty of a motor task or exist independent of the increasing cognitive demand...
January 21, 2017: Drug and Alcohol Dependence
https://www.readbyqxmd.com/read/28254456/linking-brain-vascular-physiology-to-hemodynamic-response-in-ultra-high-field-mri
#9
Kâmil Uludağ, Pablo Blinder
Functional MRI using blood oxygenation level-dependent (BOLD) contrast indirectly probes neuronal activity via evoked cerebral blood volume (CBV) and oxygenation changes. Thus, its spatio-temporal characteristics are determined by vascular physiology and MRI parameters. In this paper, we focus on the spatial distribution and time course of the fMRI signal and their magnetic field strength dependence. Even though much is still unknown, the following consistent picture is emerging: a) For high spatial resolution imaging, fMRI contrast-to-noise increases supra-linearly with field strength...
February 22, 2017: NeuroImage
https://www.readbyqxmd.com/read/28253268/multiband-multi-echo-imaging-of-simultaneous-oxygenation-and-flow-timeseries-for-resting-state-connectivity
#10
Alexander D Cohen, Andrew S Nencka, R Marc Lebel, Yang Wang
A novel sequence has been introduced that combines multiband imaging with a multi-echo acquisition for simultaneous high spatial resolution pseudo-continuous arterial spin labeling (ASL) and blood-oxygenation-level dependent (BOLD) echo-planar imaging (MBME ASL/BOLD). Resting-state connectivity in healthy adult subjects was assessed using this sequence. Four echoes were acquired with a multiband acceleration of four, in order to increase spatial resolution, shorten repetition time, and reduce slice-timing effects on the ASL signal...
2017: PloS One
https://www.readbyqxmd.com/read/28248867/structural-and-functional-brain-changes-in-early-and-mid-stage-primary-open-angle-glaucoma-using-voxel-based-morphometry-and-functional-magnetic-resonance-imaging
#11
Ming-Ming Jiang, Qing Zhou, Xiao-Yong Liu, Chang-Zheng Shi, Jian Chen, Xiang-He Huang
To investigate structural and functional brain changes in patients with primary open-angle glaucoma (POAG) by using voxel-based morphometry based on diffeomorphic anatomical registration through exponentiated Lie algebra (VBM-DARTEL) and blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI), respectively.Thirteen patients diagnosed with POAG and 13 age- and sex-matched healthy controls were enrolled in the study. For each participant, high-resolution structural brain imaging and blood flow imaging were acquired on a 3...
March 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28248433/application-of-bold-mri-and-dti-for-the-evaluation-of-renal-effect-related-to-viscosity-of-iodinated-contrast-agent-in-a-rat-model
#12
Yi Wang, Ke Ren, Yi Liu, Wen-Ge Sun, Jia-Huan Wang, Xin Zhang, Cheng-Hua Wu
PURPOSE: To evaluate the effects of viscosity of contrast agent (CA) on intrarenal oxygenation and diffusion as measured by blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) in a rat model. MATERIALS AND METHODS: Radiocontrast iodixanol formulated in three viscosities were designated 270, 320, and 350 (mg iodine/mL). Sixty-three male Wistar rats were divided into four groups. Saline and iodixanol (4 g iodine/kg) were administered...
March 1, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28241065/repeated-dexamphetamine-treatment-alters-the-dopaminergic-system-and-increases-the-phmri-response-to-methylphenidate
#13
Anouk Schrantee, Jordi L Tremoleda, Marzena Wylezinska-Arridge, Valentine Bouet, Peter Hesseling, Gideon F Meerhoff, Kora M de Bruin, Jan Koeleman, Thomas Freret, Michel Boulouard, Emilie Desfosses, Laurent Galineau, Alessandro Gozzi, François Dauphin, Willy Gsell, Jan Booij, Paul J Lucassen, Liesbeth Reneman
Dexamphetamine (AMPH) is a psychostimulant drug that is used both recreationally and as medication for attention deficit hyperactivity disorder. Preclinical studies have demonstrated that repeated exposure to AMPH can induce damage to nerve terminals of dopamine (DA) neurons. We here assessed the underlying neurobiological changes in the DA system following repeated AMPH exposure and pre-treated rats with AMPH or saline (4 times 5 mg/kg s.c., 2 hours apart), followed by a 1-week washout period. We then used pharmacological MRI (phMRI) with a methylphenidate (MPH) challenge, as a sensitive and non-invasive in-vivo measure of DAergic function...
2017: PloS One
https://www.readbyqxmd.com/read/28240722/brain-correlates-to-facial-motor-imagery-and-its-somatotopy-in-the-primary-motor-cortex
#14
Ramy S Soliman, Sanghoon Lee, Seulgi Eun, Abdalla Z Mohamed, Jeungchan Lee, Eunyoung Lee, Meena M Makary, Seung Min Kathy Lee, Hwa-Jin Lee, Woo Suk Choi, Kyungmo Park
Motor imagery (MI) has attracted increased interest for motor rehabilitation as many studies have shown that MI shares the same neural networks as motor execution (ME). Nevertheless, MI in terms of facial movement has not been studied extensively; thus, in the present study, we investigated shared neural networks between facial motor imagery (FMI) and facial motor execution (FME). In addition, FMI somatotopy within-face was investigated between the forehead and the mouth. Functional MRI was used to examine 34 healthy individuals with ME and MI paradigms for the forehead and the mouth...
March 22, 2017: Neuroreport
https://www.readbyqxmd.com/read/28240422/cerebellar-lobules-and-dentate-nuclei-mirror-cortical-force-related-bold-responses-beyond-all-linear-expectations
#15
Adnan A S Alahmadi, Matteo Pardini, Rebecca S Samson, Karl J Friston, Ahmed T Toosy, Egidio D'Angelo, Claudia A M Gandini Wheeler-Kingshott
The relationship between the BOLD response and an applied force was quantified in the cerebellum using a power grip task. To investigate whether the cerebellum responds in an on/off way to motor demands or contributes to motor responses in a parametric fashion, similarly to the cortex, five grip force levels were investigated under visual feedback. Functional MRI data were acquired in 13 healthy volunteers and their responses were analyzed using a cerebellum-optimized pipeline. This allowed us to evaluate, within the cerebellum, voxelwise linear and non-linear associations between cerebellar activations and forces...
February 27, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28226851/transcranial-focused-ultrasound-for-bold-fmri-signal-modulation-in-humans
#16
Leo Ai, Jerel K Mueller, Andrea Grant, Yigitcan Eryaman, Wynn Legon, Leo Ai, Jerel K Mueller, Andrea Grant, Yigitcan Eryaman, Wynn Legon, Andrea Grant, Wynn Legon, Yigitcan Eryaman, Leo Ai, Jerel K Mueller
Transcranial focused ultrasound (tFUS) is an emerging form of non-surgical human neuromodulation that confers advantages over existing electro and electromagnetic technologies by providing a superior spatial resolution on the millimeter scale as well as the capability to target sub-cortical structures non-invasively. An examination of the pairing of tFUS and blood oxygen level dependent (BOLD) functional MRI (fMRI) in humans is presented here.
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28216453/quantification-of-myocardial-oxygenation-in-heart-failure-using-blood-oxygen-level-dependent-t2-magnetic-resonance-imaging-comparison-with-cardiopulmonary-exercise-test
#17
Michinobu Nagao, Yuzo Yamasaki, Satoshi Kawanami, Takeshi Kamitani, Koji Sagiyama, Taiki Higo, Tomomi Ide, Atsushi Takemura, Umiko Ishizaki, Kenji Fukushima, Yuji Watanabe, Hiroshi Honda
PURPOSE: Quantification of myocardial oxygenation (MO) in heart failure (HF) has been less than satisfactory. This has necessitated the use of invasive techniques to measure MO directly or to determine the oxygen demand during exercise using the cardiopulmonary exercise (CPX) test. We propose a new quantification method for MO using blood-oxygen-level-dependent (BOLD) myocardial T2* magnetic resonance imaging (M-T2* MRI), and investigate its correlation with CPX results. METHODS: Thirty patients with refractory HF who underwent cardiac MRI and CPX test for heart transplantation, and 24 healthy, age-matched volunteers as controls were enrolled...
February 17, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28213112/laminar-imaging-of-positive-and-negative-bold-in-human-visual-cortex-at-7t
#18
Alessio Fracasso, Peter R Luijten, Serge O Dumoulin, Natalia Petridou
Deciphering the direction of information flow is critical to understand the brain. Data from non-human primate histology shows that connections between lower to higher areas (e.g. retina→V1), and between higher to lower areas (e.g. V1←V2) can be dissociated based upon the distribution of afferent synapses at the laminar level. Ultra-high field scanners opened up the possibility to image brain structure and function at an unprecedented level of detail. Taking advantage of the increased spatial resolution available, it could theoretically be possible to disentangle activity from different cortical depths from human cerebral cortex, separately studying different compartments across depth...
February 14, 2017: NeuroImage
https://www.readbyqxmd.com/read/28186661/brain-neurochemical-and-hemodynamic-findings-in-the-ny1dd-mouse-model-of-mild-sickle-cell-disease
#19
Min-Hui Cui, Sandra M Suzuka, Nicholas A Branch, Kamalakar Ambadipudi, Sangeetha Thangaswamy, Seetharama A Acharya, Henny H Billett, Craig A Branch
To characterize the cerebral profile associated with sickle cell disease (SCD), we used in vivo proton MRI and MRS to quantify hemodynamics and neurochemicals in the thalamus of NY1DD mice, a mild model of SCD, and compared them with wild-type (WT) control mice. Compared with WT mice, NY1DD mice at steady state had elevated cerebral blood flow (CBF) and concentrations of N-acetylaspartate (NAA), glutamate (Glu), alanine, total creatine and N-acetylaspartylglutamate. Concentrations of glutathione (GSH) at steady state showed a negative correlation with BOLD signal change in response to 100% oxygen, a marker for oxidative stress, and mean diffusivity assessed using diffusion-tensor imaging, a marker for edematous inflammation...
February 10, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28179153/activation-of-npffr2-leads-to-hyperalgesia-through-the-spinal-inflammatory-mediator-cgrp-in-mice
#20
Ya-Tin Lin, Ho-Ling Liu, Yuan-Ji Day, Che-Chien Chang, Po-Hung Hsu, Jin-Chung Chen
Neuropeptide FF (NPFF) is recognized as an opioid modulating peptide that regulates morphine-induced analgesia. The aim of this study was to delineate the role of NPFFR2 in pain transmission. We found the expression levels of NPFF and NPFFR2 were increased in the lumbar dorsal horn of animals with CFA- and carrageenan-induced inflammation and both NPFFR2 over-expressing transgenic (NPFFR2-Tg) and NPFFR2 agonist-treated mice displayed hyperalgesia. BOLD signals from functional MRI showed that NPFFR2-Tg mice exhibited increased activation of pain-related brain regions after painful stimulation when compared to WT mice...
February 5, 2017: Experimental Neurology
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