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https://www.readbyqxmd.com/read/29758234/a-validation-of-dynamic-causal-modelling-for-7t-fmri
#1
S Tak, J Noh, C Cheong, P Zeidman, A Razi, W D Penny, K J Friston
BACKGROUND: There is growing interest in ultra-high field magnetic resonance imaging (MRI) in cognitive and clinical neuroscience studies. However, the benefits offered by higher field strength have not been evaluated in terms of effective connectivity and dynamic causal modelling (DCM). NEW METHOD: In this study, we address the validity of DCM for 7T functional MRI data at two levels. First, we evaluate the predictive validity of DCM estimates based upon 3T and 7T in terms of reproducibility...
May 11, 2018: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/29755315/does-post-task-declarative-learning-have-an-influence-on-early-motor-memory-consolidation-over-day-an-fmri-study
#2
Inken Rothkirch, Stephan Wolff, Nils G Margraf, Anya Pedersen, Karsten Witt
Previous studies demonstrated the influence of the post-learning period on procedural motor memory consolidation. In an early period after the acquisition, motor skills are vulnerable to modifications during wakefulness. Indeed, specific interventions such as world-list learning within this early phase of motor memory consolidation seem to enhance motor performance as an indicator for successful consolidation. This finding highlights the idea that manipulations of procedural and declarative memory systems during the early phase of memory consolidation over wakefulness may influence off-line consolidation...
2018: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/29755312/integrated-fmri-preprocessing-framework-using-extended-kalman-filter-for-estimation-of-slice-wise-motion
#3
Basile Pinsard, Arnaud Boutin, Julien Doyon, Habib Benali
Functional MRI acquisition is sensitive to subjects' motion that cannot be fully constrained. Therefore, signal corrections have to be applied a posteriori in order to mitigate the complex interactions between changing tissue localization and magnetic fields, gradients and readouts. To circumvent current preprocessing strategies limitations, we developed an integrated method that correct motion and spatial low-frequency intensity fluctuations at the level of each slice in order to better fit the acquisition processes...
2018: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/29734491/oxygenation-sensitive-cardiovascular-magnetic-resonance-in-hypertensive-heart-disease-with-left-ventricular-myocardial-hypertrophy-and-non-left-ventricular-myocardial-hypertrophy-insight-from-altered-mechanics-and-cardiac-bold-imaging
#4
Bing-Hua Chen, Rui Wu, Dong-Aolei An, Ruo-Yang Shi, Qiu-Ying Yao, Qing Lu, Jiani Hu, Meng Jiang, James Deen, Ankush Chandra, Jian-Rong Xu, Lian-Ming Wu
BACKGROUND: BOLD (blood oxygen level dependent) MRI can detect regional condition of myocardial oxygen supply and demand by means of paramagnetic properties. PURPOSE: Noninvasive assessment of myocardial oxygenation by BOLD MRI in hypertensive patients with hypertension (HTN) left ventricular myocardial hypertrophy (LVMH) and HTN non-LVMH and its correlation with myocardial mechanics were performed. STUDY TYPE: Prospective. POPULATION: Twenty patients with HTN LVMH, 21 patients with HTN non-LVMH, and 23 normotensive controls were enrolled...
May 7, 2018: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29732719/evaluation-of-visceral-adipose-tissue-oxygenation-by-blood-oxygen-level-dependent-mri-in-zucker-diabetic-fatty-rats
#5
Hong-Jian Shi, Yan-Feng Li, Wen-Jie Ji, Zhi-Chun Lin, Wei Cai, Tao Chen, Bin Yuan, Xiu-Long Niu, Han-Ying Li, Wen Shu, Yu-Ming Li, Fei Yuan, Xin Zhou, Zhuoli Zhang
OBJECTIVE: This study aimed to investigate the feasibility of blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) to evaluate visceral adipose tissue (VAT) oxygenation in Zucker diabetic fatty (ZDF) rats and its associations with systemic metaflammation. METHODS: Five-week-old ZDF rats and Zucker lean (ZL) rats were fed a high-fat diet (HFD) for 18 weeks. A baseline BOLD-MRI scan of perirenal adipose tissue was performed after 8 weeks of HFD feeding, and then the rats were randomized to receive pioglitazone or a vehicle for the following 10 weeks...
May 7, 2018: Obesity
https://www.readbyqxmd.com/read/29723554/decreased-resting-state-bold-regional-homogeneity-and-the-intrinsic-functional-connectivity-within-dorsal-striatum-is-associated-with-greater-impulsivity-in-food-related-decision-making-and-bmi-change-at-6-month-follow-up
#6
Xiao Gao, Qianlin Liang, Guorong Wu, Ying She, Nan Sui, Hong Chen
Increasing animal models as well as brain imaging studies among human suggest an association between substance-related impulsivity in decision-making and decreased function of dorsal striatum. However, the resting-state intrinsic functional organization of dorsal striatum underlying food-choice impulsivity remains unknown. To address this issue, we used resting-state functional MRI (rs-fMRI) to measure brain activity among adult females. Subjects underwent the food rating task, during which they rated each food item according to their subjective perception of its taste (from Dislike it very much to Like it very much), its long term effect on health (from very unhealthy to very healthy) and decision strength to eat it (from Strong no to Strong yes)...
April 30, 2018: Appetite
https://www.readbyqxmd.com/read/29695446/functional-mri-in-the-nile-crocodile-a-new-avenue-for-evolutionary-neurobiology
#7
Mehdi Behroozi, Brendon K Billings, Xavier Helluy, Paul R Manger, Onur Güntürkün, Felix Ströckens
Crocodilians are important for understanding the evolutionary history of amniote neural systems as they are the nearest extant relatives of modern birds and share a stem amniote ancestor with mammals. Although the crocodilian brain has been investigated anatomically, functional studies are rare. Here, we employed functional magnetic resonance imaging (fMRI), never tested in poikilotherms, to investigate crocodilian telencephalic sensory processing. Juvenile Crocodylus niloticus were placed in a 7 T MRI scanner to record blood oxygenation level-dependent (BOLD) signal changes during the presentation of visual and auditory stimuli...
April 25, 2018: Proceedings. Biological Sciences
https://www.readbyqxmd.com/read/29690796/spontaneous-bold-waves-a-novel-hemodynamic-activity-in-sprague-dawley-rat-brain-detected-by-functional-magnetic-resonance-imaging
#8
Artem Shatillo, Arto Lipponen, Raimo A Salo, Heikki Tanila, Alexei Verkhratsky, Rashid Giniatullin, Olli H Gröhn
We report spontaneous hemodynamic activity termed "Spontaneous BOLD Waves" (SBWs) detected by BOLD fMRI in Sprague-Dawley rats under medetomidine anesthesia. These SBWs, which lasted several minutes, were observed in cortex, thalamus and hippocampus. The SBWs' correlates were undetectable in electrophysiological recordings, suggesting an exclusive gliovascular phenomenon dissociated from neuronal activity. SBWs were insensitive to the NMDA receptors antagonist MK-801 but were inhibited by the α1-adrenoceptor blocker prazosin...
January 1, 2018: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/29689479/lipo-prostaglandin-e1-improves-renal-hypoxia-evaluated-by-bold-mri-in-patients-with-diabetic-kidney-disease
#9
Zhi-Cheng Li, Yu-Zhe Cai, Zhi-Gang Tang, Pan-Li Zuo, Rong-Bo Liu, Fang Liu
OBJECTIVE: To evaluate the effect of lipo-PGE1 on renal hypoxia in patients with DKD by BOLD-MRI. MATERIALS AND METHODS: All patients were divided into DKD group and CKD-without-diabetes group. All patients received intravenous 10 μg lipo-PGE1 once daily for 14 days. BOLD-MRI was performed before and after lipo-PGE1 administration to acquire renal CR2* and MR2* values. RESULTS: Renal MR2* value in DKD group after lipo-PGE1 treatment were significantly decreased compared with the baseline...
April 17, 2018: Clinical Imaging
https://www.readbyqxmd.com/read/29682064/awake-craniotomy-with-noninvasive-brain-mapping-by-3-tesla-functional-magnetic-resonance-imaging-for-excision-of-low-grade-glioma-a-case-of-a-young-patient-from-pakistan
#10
Atta Ul Aleem Bhatti, Nasir Khan Jakhrani, Maria Adnan Parekh
The past few years have seen increasing support for gross total resection in the management of low-grade gliomas (LGGs), with a greater extent of resection correlated with better overall survival, progression-free survival, and time to malignant transformation. There is consistent evidence in literature supporting extent of safe resection as a good prognostic indicator as well as positively affecting seizure control, symptomatic relief in pressure symptoms, and longer progression-free and total survival. The operative goal in most LGG cases is to maximize the extent of resection for these benefits while avoiding postoperative neurologic deficits...
April 2018: Asian Journal of Neurosurgery
https://www.readbyqxmd.com/read/29681886/importance-of-collateralization-in-patients-with-large-artery-intracranial-occlusive-disease-long-term-longitudinal-assessment-of-cerebral-hemodynamic-function
#11
Larissa McKetton, Lakshmikumar Venkatraghavan, Julien Poublanc, Olivia Sobczyk, Adrian P Crawley, Casey Rosen, Frank L Silver, James Duffin, Joseph A Fisher, David J Mikulis
Patients with large artery intracranial occlusive disease (LAICOD) are at risk for both acute ischemia and chronic hypoperfusion. Collateral circulation plays an important role in prognosis, and imaging plays an essential role in diagnosis, treatment planning, and prognosis of patients with LAICOD. In addition to standard structural imaging, assessment of cerebral hemodynamic function is important to determine the adequacy of collateral supply. Among the currently available methods of assessment of cerebral hemodynamic function, measurement of cerebrovascular reactivity (CVR) using blood oxygen level-dependent (BOLD) MRI and precisely controlled CO2 has shown to be a safe, reliable, reproducible, and clinically useful method for long-term assessment of patients...
2018: Frontiers in Neurology
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
#12
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
#13
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
#14
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
#15
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
#16
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
#17
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
#18
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
#19
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
#20
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
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