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BOLD Mri

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https://www.readbyqxmd.com/read/29674739/spatial-reversal-learning-defect-coincides-with-hypersynchronous-telencephalic-bold-functional-connectivity-in-app-nl-f-nl-f-knock-in-mice
#1
Disha Shah, Amira Latif-Hernandez, Bart De Strooper, Takashi Saito, Takaomi Saido, Marleen Verhoye, Rudi D'Hooge, Annemie Van der Linden
Amyloid pathology occurs early in Alzheimer's disease (AD), and has therefore been the focus of numerous studies. Transgenic mouse models have been instrumental to study amyloidosis, but observations might have been confounded by APP-overexpression artifacts. The current study investigated early functional defects in an APP knock-in mouse model, which allows assessing the effects of pathological amyloid-beta (Aβ) without interference of APP-artifacts. Female APPNL/NL knock-in mice of 3 and 7 months old were compared to age-matched APPNL-F/NL-F mice with increased Aβ42/40 ratio and initial Aβ-plaque deposition around 6 months of age...
April 19, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29656880/fundamentals-of-functional-imaging-ii-emerging-mr-techniques-and-new-methods-of-analysis
#2
A Luna, T Martín Noguerol, L Alcalá Mata
Current multiparameter MRI protocols integrate structural, physiological, and metabolic information about cancer. Emerging techniques such as arterial spin-labeling (ASL), blood oxygen level dependent (BOLD), MR elastography, chemical exchange saturation transfer (CEST), and hyperpolarization provide new information and will likely be integrated into daily clinical practice in the near future. Furthermore, there is great interest in the study of tumor heterogeneity as a prognostic factor and in relation to resistance to treatment, and this interest is leading to the application of new methods of analysis of multiparametric protocols...
April 12, 2018: Radiología
https://www.readbyqxmd.com/read/29618992/fronto-temporal-connectivity-predicts-ect-outcome-in-major-depression
#3
Amber M Leaver, Benjamin Wade, Megha Vasavada, Gerhard Hellemann, Shantanu H Joshi, Randall Espinoza, Katherine L Narr
Background: Electroconvulsive therapy (ECT) is arguably the most effective available treatment for severe depression. Recent studies have used MRI data to predict clinical outcome to ECT and other antidepressant therapies. One challenge facing such studies is selecting from among the many available metrics, which characterize complementary and sometimes non-overlapping aspects of brain function and connectomics. Here, we assessed the ability of aggregated, functional MRI metrics of basal brain activity and connectivity to predict antidepressant response to ECT using machine learning...
2018: Frontiers in Psychiatry
https://www.readbyqxmd.com/read/29615790/multivariate-granger-causality-unveils-directed-parietal-to-prefrontal-cortex-connectivity-during-task-free-mri
#4
Andrea Duggento, Luca Passamonti, Gaetano Valenza, Riccardo Barbieri, Maria Guerrisi, Nicola Toschi
While a large body of research has focused on the study of functional brain "connectivity", few investigators have focused on directionality of brain-brain interactions which, in spite of the mostly bidirectional anatomical substrates, cannot be assumed to be symmetrical. We employ a multivariate Granger Causality-based approach to estimating directed in-network interactions and quantify its advantages using extensive realistic synthetic BOLD data simulations to match Human Connectome Project (HCP) data specification...
April 3, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29614707/best-core-stabilization-exercise-to-facilitate-subcortical-neuroplasticity-a-functional-mri-neuroimaging-study
#5
Do Hyun Kim, Jae Jin Lee, Sung Joshua Hyun You
OBJECTIVE: To investigate the effects of conscious (ADIM) and subconscious (DNS) core stabilization exercises on cortical changes in adults with core instability. PARTICIPANTS: Five non-symptomatic participants with core instability. METHODS: A novel core stabilization task switching paradigm was designed to separate cortical or subcortical neural substrates during a series of DNS or ADIM core stabilization tasks. RESULTS: fMRI blood BOLD analysis revealed a distinctive subcortical activation pattern during the performance of the DNS, whereas the cortical motor network was primarily activated during an ADIM...
March 23, 2018: Technology and Health Care: Official Journal of the European Society for Engineering and Medicine
https://www.readbyqxmd.com/read/29609518/vascular-abnormalities-within-normal-appearing-tissue-in-chronic-traumatic-brain-injury
#6
Margalit Haber, Franck Amyot, Kimbra Kenney, Tawny Meredith-Duliba, Carol Moore, Erika Silverman, Jamie Podell, Yi-Yu Chou, Dzung L Pham, John Butman, Hanzang Lu, Ramon Diaz-Arrastia, Danielle Sandsmark
Magnetic resonance imaging (MRI) is a powerful tool for visualizing traumatic brain injury(TBI)-related lesions. Trauma-induced encephalomalacia is frequently identified by its hyperintense appearance on fluid-attenuated inversion recovery (FLAIR) sequences. In addition to parenchymal lesions, TBI commonly results in cerebral microvascular injury, but its anatomic relationship to parenchymal encephalomalacia is not well characterized. The current study utilized a multimodal MRI protocol to assess microstructural tissue integrity [via mean diffusivity (MD) and fractional aniosotropy (FA)], and altered vascular function [via cerebral blood flow (CBF) and cerebral vascular reactivity (CVR)], within regions of visible encephalomalacia and normal appearing tissue in 27 chronic TBI (minimum 6 months after injury) subjects...
April 2, 2018: Journal of Neurotrauma
https://www.readbyqxmd.com/read/29608677/regional-gaba-concentrations-modulate-inter-network-resting-state-functional-connectivity
#7
Xi Chen, Xiaoying Fan, Yuzheng Hu, Chun Zuo, Susan Whitfield-Gabrieli, Daphne Holt, Qiyong Gong, Yihong Yang, Diego A Pizzagalli, Fei Du, Dost Ongur
Coordinated activity within and differential activity between large-scale neuronal networks such as the default mode network (DMN) and the control network (CN) is a critical feature of brain organization. The CN usually exhibits activations in response to cognitive tasks while the DMN shows deactivations; in addition, activity between the two networks is anti-correlated at rest. To address this issue, we used functional MRI to measure whole-brain BOLD signal during resting-state and task-evoked conditions, and MR spectroscopy (MRS) to quantify GABA and glutamate concentrations, in nodes within the DMN and CN (MPFC and DLPFC, respectively) in 19 healthy individuals at 3 Tesla...
March 28, 2018: Cerebral Cortex
https://www.readbyqxmd.com/read/29599439/fiber-optic-implant-for-simultaneous-fluorescence-based-calcium-recordings-and-bold-fmri-in-mice
#8
Felix Schlegel, Yaroslav Sych, Aileen Schroeter, Jillian Stobart, Bruno Weber, Fritjof Helmchen, Markus Rudin
Despite the growing popularity of blood oxygen level-dependent (BOLD) functional MRI (fMRI), understanding of its underlying principles is still limited. This protocol describes a technique for simultaneous measurement of neural activity using fluorescent calcium indicators together with the corresponding hemodynamic BOLD fMRI response in the mouse brain. Our early work using small-molecule fluorophores in rats gave encouraging results but was limited to acute measurements using synthetic dyes. Our latest procedure combines fMRI with optical detection of cell-type-specific virally delivered GCaMP6, a genetically encoded calcium indicator (GECI)...
May 2018: Nature Protocols
https://www.readbyqxmd.com/read/29580967/interleaved-quantitative-bold-combining-extravascular-r-2-and-intravascular-r-2-measurements-for-estimation-of-deoxygenated-blood-volume-and-hemoglobin-oxygen-saturation
#9
Hyunyeol Lee, Erin K Englund, Felix W Wehrli
Quantitative BOLD (qBOLD), a non-invasive MRI method for assessment of hemodynamic and metabolic properties of the brain in the baseline state, provides spatial maps of deoxygenated blood volume fraction (DBV) and hemoglobin oxygen saturation (HbO2 ) by means of an analytical model for the temporal evolution of free-induction-decay signals in the extravascular compartment. However, mutual coupling between DBV and HbO2 in the signal model results in considerable estimation uncertainty precluding achievement of a unique set of solutions...
March 23, 2018: NeuroImage
https://www.readbyqxmd.com/read/29580963/neurovascular-coupling-during-visual-stimulation-in-multiple-sclerosis-a-meg-fmri-study
#10
Rachael Stickland, Marek Allen, Lorenzo Magazzini, Krish D Singh, Richard G Wise, Valentina Tomassini
The process of neurovascular coupling ensures that increases in neuronal activity are fed by increases in cerebral blood flow. Evidence suggests that neurovascular coupling may be impaired in multiple sclerosis (MS) due to a combination of brain hypoperfusion, altered cerebrovascular reactivity and oxygen metabolism, and altered levels of vasoactive compounds. Here, we tested the hypothesis that neurovascular coupling is impaired in MS. We characterised neurovascular coupling as the relationship between changes in neuronal oscillatory power within the gamma frequency band (30-80 Hz), as measured by magnetoencephalography (MEG), and associated haemodynamic changes (blood oxygenation level dependent, BOLD, and cerebral blood flow, CBF)as measured by functional MRI...
March 23, 2018: Neuroscience
https://www.readbyqxmd.com/read/29572626/is-visual-activation-associated-with-changes-in-cerebral-high-energy-phosphate-levels
#11
Bart L van de Bank, Marnix C Maas, Lauren J Bains, Arend Heerschap, Tom W J Scheenen
Phosphorus magnetic resonance spectroscopy (31 P MRS) has been employed before to assess phosphocreatine (PCr) and other high-energy phosphates in the visual cortex during visual stimulation with inconsistent results. We performed functional31 P MRS imaging in the visual cortex and control regions during a visual stimulation paradigm at an unprecedented sensitivity, exploiting a dedicated RF coil design at a 7 T MR system. Visual stimulation in a 3 min 24 s on-off paradigm in eight young healthy adults generated a clear BOLD effect with traditional1 H functional MRI in the visual cortex (average z score 9...
March 23, 2018: Brain Structure & Function
https://www.readbyqxmd.com/read/29568689/both-activated-and-less-activated-regions-identified-by-functional-mri-reconfigure-to-support-task-executions
#12
Nianming Zuo, Zhengyi Yang, Yong Liu, Jin Li, Tianzi Jiang
Introduction: Functional magnetic resonance imaging (fMRI) has become very important for noninvasively characterizing BOLD signal fluctuations, which reflect the changes in neuronal firings in the brain. Unlike the activation detection strategy utilized with fMRI, which only emphasizes the synchronicity between the functional nodes (activated regions) and the task design, brain connectivity and network theory are able to decipher the interactive structure across the entire brain. However, little is known about whether and how the activated/less-activated interactions are associated with the functional changes that occur when the brain changes from the resting state to a task state...
January 2018: Brain and Behavior
https://www.readbyqxmd.com/read/29559018/%C3%AE-aminobutyric-acid-type-a-receptor-binding-affinity-in-the-right-inferior-frontal-gyrus-at-resting-state-predicts-the-performance-of-healthy-elderly-people-in-the-visual-sustained-attention-test
#13
Masato Kasagi, Tomokazu Motegi, Kosuke Narita, Kazuyuki Fujihara, Yusuke Suzuki, Minami Tagawa, Koichi Ujita, Hirotaka Shimada, Masato Fukuda
BACKGROUND: Although recent studies have suggested that the γ-aminobutyric acid type A (GABAA) receptor binding affinity can be a more sensitive marker of age-related neuronal loss than regional gray matter (GM) volume, knowledge about the relationship between decreased GABAA receptor binding affinity and cognitive decline during normal aging is still limited. METHODS: Thirty-seven healthy elderly individuals (aged 50-77 years (mean, 64.5 ± 7.3 years); 15 males and 22 females) were enrolled in this study...
March 21, 2018: International Psychogeriatrics
https://www.readbyqxmd.com/read/29555907/orthodontic-tooth-separation-activates-the-hypothalamic-area-in-the-human-brain
#14
Yoshiko Ariji, Hisataka Kondo, Ken Miyazawa, Masako Tabuchi, Syuji Koyama, Yoshitaka Kise, Akifumi Togari, Shigemi Gotoh, Eiichiro Ariji
OBJECTIVES: An animal experiment clarified that insertion of an orthodontic apparatus activated the trigeminal neurons of the medulla oblongata. Orthodontic tooth movement is known to be associated with the sympathetic nervous system and controlled by the nucleus of the hypothalamus. However, the transmission of both has not been demonstrated in humans. The purpose of this study were to examine the activated cerebral areas using brain functional magnetic resonance imaging (MRI), when orthodontic tooth separators were inserted, and to confirm the possibility of the transmission route from the medulla oblongata to the hypothalamus...
March 15, 2018: International Journal of Oral Science
https://www.readbyqxmd.com/read/29544397/decoding-intransitive-actions-in-primary-motor-cortex-using-fmri-toward-a-componential-theory-of-action-primitives-in-motor-cortex
#15
Elizabeth A Shay, Quanjing Chen, Frank E Garcea, Bradford Z Mahon
Multivoxel pattern analysis (MVPA) over functional MRI data can distinguish neural representational states that do not differ in their overall amplitude of BOLD contrast. Here we used MVPA to test whether simple intransitive actions can be distinguished in primary motor cortex. Participants rotated and flexed each of their extremities (hands and feet) during fMRI scanning. The primary motor cortex for the hand/wrist was functionally defined in each hemisphere in each subject. Within those subject-specific ROIs, we found that the average amplitude of BOLD contrast for two different movements of the contralateral hand (rotation, flexion) were higher than for the ipsilateral hand, as well as movements by both feet; however, there was no difference in amplitude between the two different types of movements for the contralateral hand...
March 16, 2018: Cognitive Neuroscience
https://www.readbyqxmd.com/read/29539614/methods-of-blood-oxygen-level-dependent-magnetic-resonance-imaging-analysis-for-evaluating-renal-oxygenation
#16
Fen Chen, Shulin Li, Dong Sun
Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI) has recently been utilized as a noninvasive tool for evaluating renal oxygenation. Several methods have been proposed for analyzing BOLD images. Regional ROI selection is the earliest and most widely used method for BOLD analysis. In the last 20 years, many investigators have used this method to evaluate cortical and medullary oxygenation in patients with ischemic nephropathy, hypertensive nephropathy, diabetic nephropathy, chronic kidney disease (CKD), acute kidney injury and renal allograft rejection...
March 8, 2018: Kidney & Blood Pressure Research
https://www.readbyqxmd.com/read/29535334/organ-specific-responses-during-brain-death-increased-aerobic-metabolism-in-the-liver-and-anaerobic-metabolism-with-decreased-perfusion-in-the-kidneys
#17
A C Van Erp, R A Rebolledo, D Hoeksma, N R Jespersen, P J Ottens, R Nørregaard, M Pedersen, C Laustsen, J G M Burgerhof, J C Wolters, J Ciapaite, H E Bøtker, H G D Leuvenink, B Jespersen
Hepatic and renal energy status prior to transplantation correlates with graft survival. However, effects of brain death (BD) on organ-specific energy status are largely unknown. We studied metabolism, perfusion, oxygen consumption, and mitochondrial function in the liver and kidneys following BD. BD was induced in mechanically-ventilated rats, inflating an epidurally-placed Fogarty-catheter, with sham-operated rats as controls. A 9.4T-preclinical MRI system measured hourly oxygen availability (BOLD-related R2*) and perfusion (T1-weighted)...
March 13, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29530447/single-pulse-tms-to-the-dlpfc-compared-to-a-matched-sham-control-induces-a-direct-causal-increase-in-caudate-cingulate-and-thalamic-bold-signal
#18
Logan T Dowdle, Truman R Brown, Mark S George, Colleen A Hanlon
BACKGROUND: In the 20 years since our group established the feasibility of performing interleaved TMS/fMRI, no studies have reported direct comparisons of active prefrontal stimulation with a matched sham. Thus, for all studies there is concern about what is truly the TMS effect on cortical neurons. OBJECTIVE: After developing a sham control for use within the MRI scanner, we used fMRI to test the hypothesis of greater regional BOLD responses for active versus control stimulation...
February 24, 2018: Brain Stimulation
https://www.readbyqxmd.com/read/29518568/evolution-of-spatial-and-temporal-features-of-functional-brain-networks-across-the-lifespan
#19
Shruti G Vij, Jason S Nomi, Dina R Dajani, Lucina Q Uddin
Development and aging are associated with functional changes in the brain across the lifespan. These changes manifest in a variety of spatial and temporal features of resting state functional MRI (rs-fMRI) but have seldom been explored exhaustively. We present a comprehensive study assessing age-related changes in spatial and temporal features of blind-source separated components identified by independent vector analysis (IVA) in a cross-sectional lifespan sample (ages 6-85 years). We show that while large-scale network configurations remain consistent throughout the lifespan, changes persist in both local and global organization of these networks...
March 6, 2018: NeuroImage
https://www.readbyqxmd.com/read/29517835/consistency-of-multiple-renal-functional-mri-measurements-over-18-months
#20
Lu-Ping Li, Jon Thacker, Wei Li, Huan Tan, Chi Wang, Orly Kohn, Stuart Sprague, Pottumarthi Prasad
BACKGROUND: Identification of patients with progressive chronic kidney disease (CKD) and those likely to respond to candidate therapeutics is urgently needed. Functional MRI measurements have shown promise. However, knowledge about the consistency of the measurements is essential to conduct longitudinal studies. PURPOSE/HYPOTHESIS: To investigate the consistency of repeated functional MRI measurements in healthy subjects. STUDY TYPE: Prospective, longitudinal study...
March 8, 2018: Journal of Magnetic Resonance Imaging: JMRI
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