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https://www.readbyqxmd.com/read/28923276/rapid-whole-brain-resting-state-fmri-at-3%C3%A2-tesla-efficiency-optimized-three-dimensional-epi-versus-repetition-time-matched-simultaneous-multi-slice-epi
#1
Rüdiger Stirnberg, Willem Huijbers, Daniel Brenner, Benedikt A Poser, Monique Breteler, Tony Stöcker
State-of-the-art simultaneous-multi-slice (SMS-)EPI and 3D-EPI share several properties that benefit functional MRI acquisition. Both sequences employ equivalent parallel imaging undersampling with controlled aliasing to achieve high temporal sampling rates. As a volumetric imaging sequence, 3D-EPI offers additional means of acceleration complementary to 2D-CAIPIRINHA sampling, such as fast water excitation and elliptical sampling. We performed an application-oriented comparison between a tailored, six-fold CAIPIRINHA-accelerated 3D-EPI protocol at 530 ms temporal and 2...
September 15, 2017: NeuroImage
https://www.readbyqxmd.com/read/28912749/functional-connectivity-of-the-corpus-callosum-in-epilepsy-patients-with-secondarily-generalized-seizures
#2
Syu-Jyun Peng, Yue-Loong Hsin
The corpus callosum (CC) plays an important role in generalization of seizure activity. We used resting-state function magnetic resonance imaging (rs-fMRI) to investigate the regional and interregional functional connectivity of CC in patients with magnetic resonance imaging (MRI)-negative and secondarily generalized seizures. We measured the multi-regional coherences of blood oxygen level-dependent (BOLD) signals via rs-fMRI, cortical thickness via high-resolution T1-weighted MRI, and white matter (WM) integrity via diffusion-tensor imaging in 16 epilepsy patients as well as in 16 age- and gender-matched healthy subjects...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28890416/bayesian-population-receptive-field-modelling
#3
REVIEW
Peter Zeidman, Edward Harry Silson, Dietrich Samuel Schwarzkopf, Chris Ian Baker, Will Penny
We introduce a probabilistic (Bayesian) framework and associated software toolbox for mapping population receptive fields (pRFs) based on fMRI data. This generic approach is intended to work with stimuli of any dimension and is demonstrated and validated in the context of 2D retinotopic mapping. The framework enables the experimenter to specify generative (encoding) models of fMRI timeseries, in which experimental stimuli enter a pRF model of neural activity, which in turns drives a nonlinear model of neurovascular coupling and Blood Oxygenation Level Dependent (BOLD) response...
September 7, 2017: NeuroImage
https://www.readbyqxmd.com/read/28885752/dual-echo-asl-contributes-to-decrypting-the-link-between-functional-connectivity-and-cerebral-blow-flow
#4
Silvia F Storti, Ilaria Boscolo Galazzo, Stefania Montemezzi, Gloria Menegaz, Francesca B Pizzini
Arterial spin labeling (ASL) MRI with a dual-echo readout module (DE-ASL) enables noninvasive simultaneous acquisition of cerebral blood flow (CBF)-weighted images and blood oxygenation level dependent (BOLD) contrast. Up to date, resting-state functional connectivity (FC) studies based on CBF fluctuations have been very limited, while the BOLD is still the method most frequently used. The purposes of this technical report were (i) to assess the potentiality of the DE-ASL sequence for the quantification of resting-state FC and brain organization, with respect to the conventional BOLD (cvBOLD) and (ii) to investigate the relationship between a series of complex network measures and the CBF information...
September 8, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28882632/spatial-specificity-of-the-functional-mri-blood-oxygenation-response-relative-to-neuronal-activity
#5
Denis Chaimow, Essa Yacoub, Kâmil Uğurbil, Amir Shmuel
Previous attempts at characterizing the spatial specificity of the blood oxygenation level dependent functional MRI (BOLD fMRI) response by estimating its point-spread function (PSF) have conventionally relied on spatial representations of visual stimuli in area V1. Consequently, their estimates were confounded by the width and scatter of receptive fields of V1 neurons. Here, we circumvent these limits by instead using the inherent cortical spatial organization of ocular dominance columns (ODCs) to determine the PSF for both Gradient Echo (GE) and Spin Echo (SE) BOLD imaging at 7 T...
September 4, 2017: NeuroImage
https://www.readbyqxmd.com/read/28868035/a-novel-stress-diathesis-model-to-predict-risk-of-post-operative-delirium-implications-for-intra-operative-management
#6
Renée El-Gabalawy, Ronak Patel, Kayla Kilborn, Caitlin Blaney, Christopher Hoban, Lawrence Ryner, Duane Funk, Regina Legaspi, Joseph A Fisher, James Duffin, David J Mikulis, W Alan C Mutch
Introduction: Risk assessment for post-operative delirium (POD) is poorly developed. Improved metrics could greatly facilitate peri-operative care as costs associated with POD are staggering. In this preliminary study, we develop a novel stress-diathesis model based on comprehensive pre-operative psychiatric and neuropsychological testing, a blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) carbon dioxide (CO2) stress test, and high fidelity measures of intra-operative parameters that may interact facilitating POD...
2017: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/28855117/how-motor-cognitive-and-musical-expertise-shapes-the-brain-focus-on-the-fmri-and-eeg-resting-state-functional-connectivity
#7
REVIEW
Pauline Cantou, Hervé Platel, Béatrice Desgranges, Mathilde Groussard
Brain activity and structure are shaped by life experiences. This plasticity has often been demonstrated with different types of expertise by using functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). Experts showed domain-specific functional neural changes during completion of a task when compared to non-experts. However, all of these results are task-dependent and even though they have proven useful for understanding neural interactions and their direct relation to individual skill, studying brain plasticity without any task might provide complementary information about functional cerebral reorganization due to expertise at the whole-brain level and might facilitate comparison across studies...
August 27, 2017: Journal of Chemical Neuroanatomy
https://www.readbyqxmd.com/read/28841675/neural-encoding-of-saltatory-pneumotactile-velocity-in-human-glabrous-hand
#8
Hyuntaek Oh, Rebecca Custead, Yingying Wang, Steven Barlow
Neurons in the somatosensory cortex are exquisitely sensitive to mechanical stimulation of the skin surface. The location, velocity, direction, and adaptation of tactile stimuli on the skin's surface are discriminable features of somatosensory processing, however the representation and processing of dynamic tactile arrays in the human somatosensory cortex are poorly understood. The principal aim of this study was to map the relation between dynamic saltatory pneumatic stimuli at discrete traverse velocities on the glabrous hand and the resultant pattern of evoked BOLD response in the human brain...
2017: PloS One
https://www.readbyqxmd.com/read/28837092/incorporating-oxygen-enhanced-mri-into-multi-parametric-assessment-of-human-prostate-cancer
#9
Heling Zhou, Rami R Hallac, Qing Yuan, Yao Ding, Zhongwei Zhang, Xian-Jin Xie, Franto Francis, Claus G Roehrborn, R Douglas Sims, Daniel N Costa, Ganesh V Raj, Ralph P Mason
Hypoxia is associated with prostate tumor aggressiveness, local recurrence, and biochemical failure. Magnetic resonance imaging (MRI) offers insight into tumor pathophysiology and recent reports have related transverse relaxation rate (R₂*) and longitudinal relaxation rate (R₁) measurements to tumor hypoxia. We have investigated the inclusion of oxygen-enhanced MRI for multi-parametric evaluation of tumor malignancy. Multi-parametric MRI sequences at 3 Tesla were evaluated in 10 patients to investigate hypoxia in prostate cancer prior to radical prostatectomy...
August 24, 2017: Diagnostics
https://www.readbyqxmd.com/read/28821668/sensory-biased-and-multiple-demand-processing-in-human-lateral-frontal-cortex
#10
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" (MD) 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)...
September 6, 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
#11
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
#12
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
#13
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
#14
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
#15
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
#16
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
#17
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
#18
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
#19
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
#20
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
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