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BOLD Mri

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https://www.readbyqxmd.com/read/28821668/sensory-biased-and-multiple-demand-processing-in-human-lateral-frontal-cortex
#1
Abigail L Noyce, Nishmar Cestero, Samantha W Michalka, Barbara G Shinn-Cunningham, David C Somers
The functionality of much of human lateral frontal cortex (LFC) has been characterized as 'multiple demand' as these regions appear to support a broad range of cognitive tasks. In contrast to this domain-general account, recent evidence indicates that portions of LFC are consistently selective for sensory modality. Michalka et al. (2015) reported two bilateral regions that are biased for visual attention, superior precentral sulcus (sPCS) and inferior precentral sulcus (iPCS), interleaved with two bilateral regions that are biased for auditory attention, transverse gyrus intersecting precentral sulcus (tgPCS) and caudal inferior frontal sulcus (cIFS)...
August 8, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28815879/calibrated-imaging-reveals-altered-grey-matter-metabolism-related-to-white-matter-microstructure-and-symptom-severity-in-multiple-sclerosis
#2
Nicholas A Hubbard, Monroe P Turner, Minhui Ouyang, Lyndahl Himes, Binu P Thomas, Joanna L Hutchison, Shawheen Faghihahmadabadi, Scott L Davis, Jeremy F Strain, Jeffrey Spence, Daniel C Krawczyk, Hao Huang, Hanzhang Lu, John Hart, Teresa C Frohman, Elliot M Frohman, Darin T Okuda, Bart Rypma
Multiple sclerosis (MS) involves damage to white matter microstructures. This damage has been related to grey matter function as measured by standard, physiologically-nonspecific neuroimaging indices (i.e., blood-oxygen-level dependent signal [BOLD]). Here, we used calibrated functional magnetic resonance imaging and diffusion tensor imaging to examine the extent to which specific, evoked grey matter physiological processes were associated with white matter diffusion in MS. Evoked changes in BOLD, cerebral blood flow (CBF), and oxygen metabolism (CMRO2 ) were measured in visual cortex...
August 16, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28815863/decoding-fmri-events-in-sensorimotor-motor-network-using-sparse-paradigm-free-mapping-and-activation-likelihood-estimates
#3
Francisca M Tan, César Caballero-Gaudes, Karen J Mullinger, Siu-Yeung Cho, Yaping Zhang, Ian L Dryden, Susan T Francis, Penny A Gowland
Most functional MRI (fMRI) studies map task-driven brain activity using a block or event-related paradigm. Sparse paradigm free mapping (SPFM) can detect the onset and spatial distribution of BOLD events in the brain without prior timing information, but relating the detected events to brain function remains a challenge. In this study, we developed a decoding method for SPFM using a coordinate-based meta-analysis method of activation likelihood estimation (ALE). We defined meta-maps of statistically significant ALE values that correspond to types of events and calculated a summation overlap between the normalized meta-maps and SPFM maps...
August 16, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28805936/characterizing-hypoxia-in-human-glioma-a-simultaneous-multimodal-mri-and-pet-study
#4
Christine Preibisch, Kuangyu Shi, Anne Kluge, Mathias Lukas, Benedikt Wiestler, Jens Göttler, Jens Gempt, Florian Ringel, Mohamed Al Jaberi, Jürgen Schlegel, Bernhard Meyer, Claus Zimmer, Thomas Pyka, Stefan Förster
Hypoxia plays an important role for the prognosis and therapy response of cancer. Thus, hypoxia imaging would be a valuable tool for pre-therapeutic assessment of tumor malignancy. However, there is no standard validated technique for clinical application available yet. Therefore, we performed a study in 12 patients with high-grade glioma, where we directly compared the two currently most promising techniques, namely the MR-based relative oxygen extraction fraction (MR-rOEF) and the PET hypoxia marker H-1-(3-[(18) F]-fluoro-2-hydroxypropyl)-2-nitroimidazole ([(18) F]-FMISO)...
August 14, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28804779/language-mapping-using-t2-prepared-bold-functional-mri-in-the-presence-of-large-susceptibility-artifacts-initial-results-in-patients-with-brain-tumor-and-epilepsy
#5
Jun Hua, Xinyuan Miao, Shruti Agarwal, Chetan Bettegowda, Alfredo Quiñones-Hinojosa, John Laterra, Peter C M Van Zijl, James J Pekar, Jay J Pillai
At present, presurgical functional mapping is the most prevalent clinical application of functional magnetic resonance imaging (fMRI). Signal dropouts and distortions caused by susceptibility effects in the current standard echo planar imaging (EPI)-based fMRI images are well-known problems and pose a major hurdle for the application of fMRI in several brain regions, many of which are related to language mapping in presurgical planning. Such artifacts are particularly problematic in patients with previous surgical resection cavities, craniotomy hardware, hemorrhage, and vascular malformation...
June 2017: Tomography: a Journal for Imaging Research
https://www.readbyqxmd.com/read/28789608/blood-oxygen-level-dependent-magnetic-resonance-imaging-for-detecting-pathological-patterns-in-patients-with-lupus-nephritis-a-preliminary-study-using-gray-level-co-occurrence-matrix-analysis
#6
Huilan Shi, Junya Jia, Dong Li, Li Wei, Wenya Shang, Zhenfeng Zheng
Objective Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI) is a noninvasive technique useful in patients with renal disease. The current study was performed to determine whether BOLD MRI can contribute to the diagnosis of renal pathological patterns. Methods BOLD MRI was used to obtain functional magnetic resonance parameter R2* values. Gray-level co-occurrence matrixes (GLCMs) were generated for gray-scale maps. Several GLCM parameters were calculated and used to construct algorithmic models for renal pathological patterns...
January 1, 2017: Journal of International Medical Research
https://www.readbyqxmd.com/read/28783763/mapping-altered-brain-connectivity-and-its-clinical-associations-in-adult-moyamoya-disease-a-resting-state-functional-mri-study
#7
Ken Kazumata, Khin Khin Tha, Haruto Uchino, Masaki Ito, Naoki Nakayama, Takeo Abumiya
Detection of subtle ischemic injuries in moyamoya disease may enable optimization of timing of revascularization surgery, and could potentially improve functional outcomes. Resting-state functional magnetic resonance imaging (rs-fMRI) is widely used to study functional organization of the brain, but it remains unclear whether rs-fMRI could elucidate distinct characteristics in moyamoya disease. Here, we aimed to determine changes in a conventional rs-fMRI measure and analyze any associations with clinical symptoms and cerebral hemodynamics...
2017: PloS One
https://www.readbyqxmd.com/read/28772233/functional-mri-based-identification-of-brain-regions-activated-by-mechanical-noxious-stimulation-and-modulatory-effect-of-remifentanil-in-cats
#8
Dai Nagakubo, Yuji Hamamoto, Daisuke Hasegawa, Masatoshi Kamata, Tomoya Iizuka, Kanako Muta, Naoki Fujita, Takayuki Nakagawa, Ryohei Nishimura
This study was conducted to identify the brain regions corresponding to mechanical noxious stimulation in cats using functional magnetic resonance imaging (fMRI) and to investigate the modulatory effect of remifentanil on the activation of these regions. Six healthy cats were anesthetized using a constant-rate infusion of alfaxalone. Cats were allocated to one of three treatment groups: remifentanil 0 (saline), 0.25, and 0.5μg/kg/min. A 3.0-T MRI unit was used to collect fMRI data. During the fMRI scanning, mechanical noxious stimulation was applied by tail clamping...
July 24, 2017: Research in Veterinary Science
https://www.readbyqxmd.com/read/28770549/therapy-related-longitudinal-brain-perfusion-changes-in-patients-with-chronic-pelvic-pain-syndrome
#9
Christian Weisstanner, Livio Mordasini, George N Thalmann, Rajeev K Verma, Christian Rummel, Andrea Federspiel, Thomas M Kessler, Roland Wiest
BACKGROUND: The imaging method most frequently employed to identify brain areas involved in neuronal processing of nociception and brain pain perception is blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI). Arterial spin labelling (ASL), in contrast, offers advantages when slow varying changes in brain function are investigated. Chronic pelvic pain syndrome (CPPS) is a disorder of, mostly, young males that leads to altered pain perceptions in structures related to the pelvis...
August 3, 2017: Swiss Medical Weekly
https://www.readbyqxmd.com/read/28758118/human-brain-mapping-of-visual-script-familiarity-between-phonological-and-logographic-language-3%C3%A2-t-functional-mri-study
#10
Nambeom Kim, Jongho Kim, Chang-Ki Kang, Chan-A Park, Mi-Ra Lim, Young-Bo Kim, Byung-Gee Bak
Neurolinguistic circuitry for two different scripts of language, such as phonological scripts (PhonoS) versus logographic scripts (LogoS) (e.g., English versus Chinese, resp.), recruits segregated neural pathways according to orthographic regularity (OrthoR). The purpose of this study was to identify the effect of VSF for cortical representation according to different OrthoR to represent Hangul versus Hanja as PhonoS versus LogoS, respectively. A total of 24 right-handed, native Korean undergraduate students with the first language of PhonoS and the second language of LogoS were divided into high- or low-competent groups for L2 of LogoS...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28739119/structural-and-functional-empirical-and-modeled-connectivity-in-the-cerebral-cortex-of-the-rat
#11
Antonio Díaz-Parra, Zachary Osborn, Santiago Canals, David Moratal, Olaf Sporns
Connectomics data from animal models provide an invaluable opportunity to reveal the complex interplay between structure and function in the mammalian brain. In this work, we investigate the relationship between structural and functional connectivity in the rat brain cortex using a directed anatomical network generated from a carefully curated meta-analysis of published tracing data, along with resting-state functional MRI data obtained from a group of 14 anesthetized Wistar rats. We found a high correspondence between the strength of functional connections, measured as blood oxygen level dependent (BOLD) signal correlations between cortical regions, and the weight of the corresponding anatomical links in the connectome graph (maximum Spearman rank-order correlation ρ=0...
July 21, 2017: NeuroImage
https://www.readbyqxmd.com/read/28734059/localized-reductions-in-resting-state-functional-connectivity-in-children-with-prenatal-alcohol-exposure
#12
Jia Fan, Paul A Taylor, Sandra W Jacobson, Christopher D Molteno, Suril Gohel, Bharat B Biswal, Joseph L Jacobson, Ernesta M Meintjes
Fetal alcohol spectrum disorders (FASD) are characterized by impairment in cognitive function that may or may not be accompanied by craniofacial anomalies, microcephaly, and/or growth retardation. Resting-state functional MRI (rs-fMRI), which examines the low-frequency component of the blood oxygen level dependent (BOLD) signal in the absence of an explicit task, provides an efficient and powerful mechanism for studying functional brain networks even in low-functioning and young subjects. Studies using independent component analysis (ICA) have identified a set of resting-state networks (RSNs) that have been linked to distinct domains of cognitive and perceptual function, which are believed to reflect the intrinsic functional architecture of the brain...
July 22, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28725547/spatial-working-memory-in-neurofibromatosis-1-altered-neural-activity-and-functional-connectivity
#13
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/28708550/unsupervised-myocardial-segmentation-for-cardiac-bold
#14
Ilkay Oksuz, Anirban Mukhopadhyay, Rohan Dharmakumar, Sotirios A Tsaftaris
A fully automated 2D+time myocardial segmentation framework is proposed for Cardiac Magnetic Resonance (CMR) Blood-Oxygen-Level-Dependent (BOLD) datasets. Ischemia detection with CINE BOLD CMR relies on spatiotemporal patterns in myocardial intensity but these patterns also trouble supervised segmentation methods, the de-facto standard for myocardial segmentation in cine MRI. Segmentation errors severely undermine the accurate extraction of these patterns. In this paper we build a joint motion and appearance method that relies on dictionary learning to find a suitable subspace...
July 12, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28693449/multiparametric-magnetic-resonance-imaging-in-mucosal-primary-head-and-neck-cancer-a-prospective-imaging-biomarker-study
#15
Christopher N Rumley, Mark T Lee, Lois Holloway, Robba Rai, Myo Min, Dion Forstner, Allan Fowler, Gary Liney
BACKGROUND: Radical radiotherapy, with or without concomitant chemotherapy forms the mainstay of organ preservation approaches in mucosal primary head and neck cancer. Despite technical advances in cancer imaging and radiotherapy administration, a significant proportion of patients fail to achieve a complete response to treatment. For those patients who do achieve a complete response, acute and late toxicities remain a cause of morbidity. A critical need therefore exists for imaging biomarkers which are capable of informing patient selection for both treatment intensification and de-escalation strategies...
July 10, 2017: BMC Cancer
https://www.readbyqxmd.com/read/28692137/portable-perfusion-phantom-for-quantitative-dce-mri-of-the-abdomen
#16
Harrison Kim, Mina Mousa, Patrick Schexnailder, Robert Hergenrother, Mark Bolding, Bernard Ntsikoussalabongui, Vinoy Thomas, Desiree E Morgan
PURPOSE: To develop a portable perfusion phantom and validate its utility in quantitative dynamic contrast-enhanced magnetic resonance imaging of the abdomen. METHODS: A portable perfusion phantom yielding a reproducible contrast enhancement curve (CEC) was developed. A phantom package including perfusion and static phantoms were imaged simultaneously with each of three healthy human volunteers in two different 3T MR scanners. Look-up tables correlating reference (known) contrast concentrations with measured ones were created using either the static or perfusion phantom...
July 10, 2017: Medical Physics
https://www.readbyqxmd.com/read/28687521/simultaneous-gcamp6-based-fiber-photometry-and-fmri-in-rats
#17
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/28687517/comparing-test-retest-reliability-of-dynamic-functional-connectivity-methods
#18
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
#19
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/28686073/effect-of-hypoxia-on-bold-fmri-response-and-total-cerebral-blood-flow-in-migraine-with-aura-patients
#20
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
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