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Functional magnetic resonance imaging

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https://www.readbyqxmd.com/read/28544994/12h-abstinence-induced-right-anterior-insula-network-pattern-changes-in-young-smokers
#1
Yanzhi Bi, Yajuan Zhang, Yangding Li, Dahua Yu, Kai Yuan, Jie Tian
BACKGROUND: The strong craving to smoke is a core factor of smoking abstinence that precipitates relapse. Insula plays critical roles in maintaining nicotine dependence, especially in the interoceptive awareness of craving. Despite evidence indicating a link between insula and abstinence-induced craving, less is known about the neural basis of abstinence-induced craving from the circuit level of insula. METHODS: The present study examined the effects of 12h of abstinence from smoking on the resting state functional connectivity (RSFC) of anterior (AI) and posterior insula in young smokers using a within-subject design...
May 15, 2017: Drug and Alcohol Dependence
https://www.readbyqxmd.com/read/28544942/behavioural-and-neural-evidence-for-the-impact-of-fluency-context-on-conscious-memory
#2
Carlos Alexandre Gomes, Axel Mecklinger, Hubert Zimmer
It has been recently suggested that fluency may impact recognition memory performance when the fluency context varies from trial-to-trial. Surprisingly, such an effect has proved difficult to detect in the masked priming paradigm, one of the most popular means to increase fluency-based memory judgements. We conducted a functional magnetic resonance imaging (fMRI) experiment in which participants encoded words at study and, at test, performed a recognition memory task within a masked priming procedure. In order to optimise the chances of finding priming effects on recognition memory performance, we used low-frequency words, which have been shown to increase hits relative to false alarms and enhance masked priming effects...
April 21, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
https://www.readbyqxmd.com/read/28544904/decreased-prefrontal-functional-brain-response-during-memory-testing-in-women-with-cushing-s-syndrome-in-remission
#3
Oskar Ragnarsson, Andreas Stomby, Per Dahlqvist, Johan A Evang, Mats Ryberg, Tommy Olsson, Jens Bollerslev, Lars Nyberg, Gudmundur Johannsson
Neurocognitive dysfunction is an important feature of Cushing's syndrome (CS). Our hypothesis was that patients with CS in remission have decreased functional brain responses in the prefrontal cortex and hippocampus during memory testing. In this cross-sectional study we included 19 women previously treated for CS and 19 controls matched for age, gender, and education. The median remission time was 7 (IQR 6-10) years. Brain activity was studied with functional magnetic resonance imaging during episodic- and working-memory tasks...
May 12, 2017: Psychoneuroendocrinology
https://www.readbyqxmd.com/read/28544456/the-experience-of-beauty-derived-from-sorrow
#4
Tomohiro Ishizu, Semir Zeki
We studied the neural mechanisms that are engaged during the experience of beauty derived from sorrow and from joy, two experiences that share a common denominator (beauty) but are linked to opposite emotional valences. Twenty subjects viewed and rerated, in a functional magnetic resonance imaging scanner, 120 images which each had classified into the following four categories: beautiful and sad; beautiful and joyful; neutral; ugly. The medial orbito-frontal cortex (mOFC) was active during the experience of both types of beauty...
May 23, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28544426/the-catechol-o-methyltransferase-comt-val158met-genotype-modulates-working-memory-related-dorsolateral-prefrontal-response-and-performance-in-bipolar-disorder
#5
K W Miskowiak, H L Kjaerstad, M M Støttrup, A M Svendsen, K M Demant, L K Hoeffding, T M Werge, K E Burdick, K Domschke, A F Carvalho, E Vieta, M Vinberg, L V Kessing, H R Siebner, J Macoveanu
OBJECTIVES: Cognitive dysfunction affects a substantial proportion of patients with bipolar disorder (BD), and genetic-imaging paradigms may aid in the elucidation of mechanisms implicated in this symptomatic domain. The Val allele of the functional Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene is associated with reduced prefrontal cortex dopamine and exaggerated working memory-related prefrontal activity. This functional magnetic resonance imaging (fMRI) study investigated for the first time whether the COMT Val158Met genotype modulates prefrontal activity during spatial working memory in BD...
May 23, 2017: Bipolar Disorders
https://www.readbyqxmd.com/read/28544256/intrinsic-functional-connectivity-alterations-in-progressive-supranuclear-palsy-differential-effects-in-frontal-cortex-motor-and-midbrain-networks
#6
Johannes Rosskopf, Martin Gorges, Hans-Peter Müller, Dorothée Lulé, Ingo Uttner, Albert C Ludolph, Elmar Pinkhardt, Freimut D Juengling, Jan Kassubek
BACKGROUND: The topography of functional network changes in progressive supranuclear palsy can be mapped by intrinsic functional connectivity MRI. The objective of this study was to study functional connectivity and its clinical and behavioral correlates in dedicated networks comprising the cognition-related default mode and the motor and midbrain functional networks in patients with PSP. METHODS: Whole-brain-based "resting-state" functional MRI and high-resolution T1-weighted magnetic resonance imaging data together with neuropsychological and video-oculographic data from 34 PSP patients (22 with Richardson subtype and 12 with parkinsonian subtype) and 35 matched healthy controls were subjected to network-based functional connectivity and voxel-based morphometry analysis...
May 22, 2017: Movement Disorders: Official Journal of the Movement Disorder Society
https://www.readbyqxmd.com/read/28543731/neuroimaging-biomarkers-and-impaired-olfaction-in-cognitively-normal-individuals
#7
Maria Vassilaki, Teresa J Christianson, Michelle M Mielke, Yonas E Geda, Walter K Kremers, Mary M Machulda, David S Knopman, Ronald C Petersen, Val J Lowe, Clifford R Jack, Rosebud O Roberts
OBJECTIVE: There is a need for inexpensive non-invasive tests to identify older healthy persons at risk for Alzheimer's disease (AD) for enrollment in AD prevention trials. Our objective was to examine whether abnormalities in neuroimaging measures of amyloid and neurodegeneration are correlated with odor identification (OI) in the population-based Mayo Clinic Study of Aging (MCSA). METHODS: Cognitively normal (CN) participants had olfactory function assessed using the Brief Smell Identification Test (B-SIT), underwent magnetic resonance imaging (MRI; n=829) to assess a composite Alzheimer's disease (AD) signature cortical thickness and hippocampal volume (HVa), and, (11) C-Pittsburgh compound B ((11) C-PiB; n=306) and (18) fluorodeoxyglucose ((18) F-FDG; n=305) positron emission tomography (PET) scanning to assess amyloid accumulation and brain hypometabolism, respectively...
May 22, 2017: Annals of Neurology
https://www.readbyqxmd.com/read/28543545/heat-girdling-does-not-affect-xylem-integrity-an-in%C3%A2-vivo-magnetic-resonance-imaging-study-in-the-tomato-peduncle
#8
Bart A E Van de Wal, Carel W Windt, Olivier Leroux, Kathy Steppe
Heat girdling is a method to estimate the relative contribution of phloem vs xylem water flow to fruit growth. The heat girdling process is assumed to destroy all living tissues, including the phloem, without affecting xylem conductivity. However, to date, the assumption that xylem is not affected by heat girdling remains unproven. In this study, we used in vivo magnetic resonance imaging (MRI) velocimetry to test if heat girdling can cause xylem vessels to embolize or affect xylem water flow characteristics in the peduncle of tomato (Solanum lycopersicum cv Dirk)...
May 22, 2017: New Phytologist
https://www.readbyqxmd.com/read/28542926/effect-of-spironolactone-on-exercise-tolerance-and-arterial-function-in-older-adults-with-heart-failure-with-preserved-ejection-fraction
#9
Bharathi Upadhya, William G Hundley, Peter H Brubaker, Timothy M Morgan, Kathryn P Stewart, Dalane W Kitzman
OBJECTIVES: To evaluate the effects of an aldosterone antagonist on exercise intolerance in older adults with heart failure and preserved ejection fraction (HFpEF). DESIGN: Randomized, placebo-controlled, double-blind trial. SETTING: Academic medical center, Winston-Salem, North Carolina. PARTICIPANTS: Older adults (N = 80, aged 71 ± 1; 80% female) with stable compensated HFpEF and controlled blood pressure (BP)...
May 19, 2017: Journal of the American Geriatrics Society
https://www.readbyqxmd.com/read/28542743/neuroimaging-cardiovascular-physiology-and-functional-outcomes-in-infants-with-congenital-heart-disease
#10
REVIEW
Nathalie H P Claessens, Christopher J Kelly, Serena J Counsell, Manon J N L Benders
This review integrates data on brain dysmaturation and acquired brain injury using fetal and neonatal magnetic resonance imaging (MRI), including the contribution of cardiovascular physiology to differences in brain development, and the relationship between brain abnormalities and subsequent neurological impairments in infants with congenital heart disease (CHD). The antenatal and neonatal period are critical for optimal brain development; the developing brain is particularly vulnerable to haemodynamic disturbances during this time...
May 19, 2017: Developmental Medicine and Child Neurology
https://www.readbyqxmd.com/read/28542116/prevalence-and-clinical-characteristics-of-spontaneous-splenorenal-shunt-in-liver-cirrhosis-a-retrospective-observational-study-based-on-contrast-enhanced-computed-tomography-ct-and-magnetic-resonance-imaging-mri-scans
#11
Xingshun Qi, Xiaolong Qi, Yongguo Zhang, Xiaodong Shao, Chunyan Wu, Yongji Wang, Ran Wang, Xintong Zhang, Han Deng, Feifei Hou, Jing Li, Xiaozhong Guo
BACKGROUND This is a retrospective observational study evaluating the prevalence and clinical characteristics of spontaneous splenorenal shunt in liver cirrhosis. MATERIAL AND METHODS We included a total of 105 cirrhotic patients who were admitted to our hospital between June 2012 and December 2013 and underwent contrast-enhanced CT and/or MRI scans at admissions. Spontaneous splenorenal shunt was identified. Clinical and laboratory data were compared between cirrhotic patients with and without spontaneous splenorenal shunt...
May 25, 2017: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
https://www.readbyqxmd.com/read/28541428/dissociable-roles-of-cerebral-%C3%AE-opioid-and-type-2-dopamine-receptors-in-vicarious-pain-a-combined-pet-fmri-study
#12
Tomi Karjalainen, Henry K Karlsson, Juha M Lahnakoski, Enrico Glerean, Pirjo Nuutila, Iiro P Jääskeläinen, Riitta Hari, Mikko Sams, Lauri Nummenmaa
Neuroimaging studies have shown that seeing others in pain activates brain regions that are involved in first-hand pain, suggesting that shared neuromolecular pathways support processing of first-hand and vicarious pain. We tested whether the dopamine and opioid neurotransmitter systems involved in nociceptive processing also contribute to vicarious pain experience. We used in vivo positron emission tomography to quantify type 2 dopamine and μ-opioid receptor (D2R and MOR, respectively) availabilities in brains of 35 subjects...
May 24, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/28541256/modulation-of-brainstem-activity-and-connectivity-by-respiratory-gated-auricular-vagal-afferent-nerve-stimulation-in-migraine-patients
#13
Ronald G Garcia, Richard L Lin, Jeungchan Lee, Jieun Kim, Riccardo Barbieri, Roberta Sclocco, Ajay D Wasan, Robert R Edwards, Bruce R Rosen, Nouchine Hadjikhani, Vitaly Napadow
Migraine pathophysiology includes altered brainstem excitability, and recent neuromodulatory approaches aimed at controlling migraine episodes have targeted key brainstem relay and modulatory nuclei. In this study, we evaluated the impact of respiratory-gated auricular vagal afferent nerve stimulation (RAVANS), a novel neuromodulatory intervention based on an existing transcutaneous vagus nerve stimulation approach, in the modulation of brainstem activity and connectivity in migraine patients. We applied 3T-functional magnetic resonance imaging with improved in-plane spatial resolution (2...
April 25, 2017: Pain
https://www.readbyqxmd.com/read/28541186/distributed-patterns-of-brain-activity-underlying-real-time-fmri-neurofeedback-training
#14
Rotem Kopel, Kirsten Emmert, Frank Scharnowski, Sven Haller, Dimitri Van De Ville
Neurofeedback (NF) based on real-time functional magnetic resonance imaging (rt-fMRI) is an exciting neuroimaging application. In most rt-fMRI NF studies, the activity level of a single region of interest (ROI) is provided as a feedback signal and the participants are trained to up or down regulate the feedback signal. NF training effects are typically analyzed using a confirmatory univariate approach, i.e., changes in the target ROI are explained by a univariate linear modulation. However, learning to self-regulate the ROI activity through NF is mediated by distributed changes across the brain...
June 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28541130/measuring-functional-connectivity-in-stroke-approaches-and-considerations
#15
Joshua S Siegel, Gordon L Shulman, Maurizio Corbetta
Recent research has demonstrated the importance of global changes to the functional organization of brain network following stroke. Resting functional magnetic resonance imaging (R-fMRI) is a non-invasive tool that enables the measurement of functional connectivity (FC) across the entire brain while placing minimal demands on the subject. For these reasons, it is a uniquely appealing tool for studying the distant effects of stroke. However, R-fMRI studies rely on a number of premises that cannot be assumed without careful validation in the context of stroke...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28540647/the-integration-of-social-influence-and-reward-computational-approaches-and-neural-evidence
#16
Damon Tomlin, Andrea Nedic, Deborah A Prentice, Philip Holmes, Jonathan D Cohen
Decades of research have established that decision-making is dramatically impacted by both the rewards an individual receives and the behavior of others. How do these distinct influences exert their influence on an individual's actions, and can the resulting behavior be effectively captured in a computational model? To address this question, we employed a novel spatial foraging game in which groups of three participants sought to find the most rewarding location in an unfamiliar two-dimensional space. As the game transitioned from one block to the next, the availability of information regarding other group members was varied systematically, revealing the relative impacts of feedback from the environment and information from other group members on individual decision-making...
May 24, 2017: Cognitive, Affective & Behavioral Neuroscience
https://www.readbyqxmd.com/read/28540400/imaging-of-cerebral-ischemic-edema-and-neuronal-death
#17
REVIEW
Rüdiger von Kummer, Imanuel Dzialowski
PURPOSE: In acute cerebral ischemia, the assessment of irreversible injury is crucial for treatment decisions and the patient's prognosis. There is still uncertainty how imaging can safely differentiate reversible from irreversible ischemic brain tissue in the acute phase of stroke. METHODS: We have searched PubMed and Google Scholar for experimental and clinical papers describing the pathology and pathophysiology of cerebral ischemia under controlled conditions...
May 24, 2017: Neuroradiology
https://www.readbyqxmd.com/read/28540067/utility-of-cardiac-magnetic-resonance-for-evaluation-of-mitral-regurgitation-prior-to-mitral-valve-surgery
#18
REVIEW
Neil K Mehta, Jiwon Kim, Jonathan Y Siden, Sara Rodriguez-Diego, Javid Alakbarli, Antonino Di Franco, Jonathan W Weinsaft
Mitral regurgitation (MR) is a common cause of morbidity worldwide and an accepted indication for interventional therapies which aim to reduce or resolve adverse clinical outcomes associated with MR. Cardiac magnetic resonance (CMR) provides highly accurate means of assessing MR, including a variety of approaches that can measure MR based on quantitative flow. Additionally, CMR is widely accepted as a reference standard for cardiac chamber quantification, enabling reliable detection of subtle changes in cardiac chamber size and function so as to guide decision-making regarding timing of mitral valve directed therapies...
April 2017: Journal of Thoracic Disease
https://www.readbyqxmd.com/read/28540066/cine-cmr-partial-voxel-segmentation-demonstrates-increased-aortic-stiffness-among-patients-with-marfan-syndrome
#19
Parmanand Singh, Zaid Almarzooq, Noel C F Codell, Yi Wang, Mary J Roman, Richard B Devereux, Jonathan W Weinsaft
BACKGROUND: Standard cine-cardiac magnetic resonance (CMR) imaging is commonly used to evaluate cardiac structure, geometry and function. Prior studies have shown that automated segmentation via partial voxel interpolation (PVI) accurately quantifies phantom-based cardiac chamber volumes and necropsy left ventricular myocardial mass. Despite this, the applicability and usefulness of PVI in the determination of physiologic parameters of the aorta such as aortic stiffness has yet to be investigated...
April 2017: Journal of Thoracic Disease
https://www.readbyqxmd.com/read/28540065/dynamic-and-quantitative-evaluation-of-degenerative-mitral-valve-disease-a-dedicated-framework-based-on-cardiac-magnetic-resonance-imaging
#20
Francesco Sturla, Francesco Onorati, Giovanni Puppini, Omar A Pappalardo, Matteo Selmi, Emiliano Votta, Giuseppe Faggian, Alberto Redaelli
BACKGROUND: Accurate quantification of mitral valve (MV) morphology and dynamic behavior over the cardiac cycle is crucial to understand the mechanisms of degenerative MV dysfunction and to guide the surgical intervention. Cardiac magnetic resonance (CMR) imaging has progressively been adopted to evaluate MV pathophysiology, although a dedicated framework is required to perform a quantitative assessment of the functional MV anatomy. METHODS: We investigated MV dynamic behavior in subjects with normal MV anatomy (n=10) and patients referred to surgery due to degenerative MV prolapse, classified as fibro-elastic deficiency (FED, n=9) and Barlow's disease (BD, n=10)...
April 2017: Journal of Thoracic Disease
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