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BOLD fMRI

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https://www.readbyqxmd.com/read/28815863/decoding-fmri-events-in-sensorimotor-motor-network-using-sparse-paradigm-free-mapping-and-activation-likelihood-estimates
#1
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/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
#2
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/28803941/fast-imaging-for-mapping-dynamic-networks
#3
REVIEW
Pierre LeVan, Burak Akin, Jürgen Hennig
The development of highly accelerated fMRI acquisition techniques has led to novel possibilities to monitor cerebral activity non-invasively and with unprecedented temporal resolutions. With the emergence of dynamic connectivity and its ability to provide a much richer characterization of brain function compared to static measures, fast fMRI may yet play a crucial role in tracking dynamically varying networks. In spite of the dominance of slow hemodynamic contributions to the BOLD signal, high temporal sampling rates nevertheless improve the measurement of physiological noise, yielding an exceptional sensitivity for the detection of periods of transient connectivity at time scales of a few tens of seconds...
August 10, 2017: NeuroImage
https://www.readbyqxmd.com/read/28802988/does-education-play-a-role-in-language-reorganization-after-surgery-in-drug-refractory-temporal-lobe-epilepsy-an-fmri-based-study
#4
Kapil Chaudhary, Bhargavi Ramanujam, S Senthil Kumaran, P Sarat Chandra, Ashima Nehra Wadhawan, Ajay Garg, Manjari Tripathi
OBJECTIVES: Patients with drug refractory epilepsy (DRE) and a high level of education may differ in their language recovery after surgery. Our aim was to determine whether there were differences in the extent of improvement and pattern of reorganization of language functions on functional magnetic resonance imaging (fMRI) after surgery to treat refractory temporal lobe epilepsy (TLE) between patients with more than 12 years of formal education versus those with a shorter period of regular schooling...
July 29, 2017: Epilepsy Research
https://www.readbyqxmd.com/read/28798694/decomposing-multifractal-crossovers
#5
Zoltan Nagy, Peter Mukli, Peter Herman, Andras Eke
Physiological processes-such as, the brain's resting-state electrical activity or hemodynamic fluctuations-exhibit scale-free temporal structuring. However, impacts common in biological systems such as, noise, multiple signal generators, or filtering by transport function, result in multimodal scaling that cannot be reliably assessed by standard analytical tools that assume unimodal scaling. Here, we present two methods to identify breakpoints or crossovers in multimodal multifractal scaling functions. These methods incorporate the robust iterative fitting approach of the focus-based multifractal formalism (FMF)...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28794972/fractional-amplitude-of-low-frequency-fluctuations-falff-in-post-stroke-depression
#6
Natalia Egorova, Michele Veldsman, Toby Cumming, Amy Brodtmann
Depression is a common outcome following stroke, associated with reduced quality of life and poorer recovery. Despite attempts to associate depression symptoms with specific lesion sites, the neural basis of post-stroke depression remains poorly understood. Resting state fMRI has provided new insights into the neural underpinnings of post-stroke depression, but has been limited to connectivity analyses exploring interregional correlations in the time-course of activity. Other aspects of resting state BOLD signal remain unexamined...
2017: NeuroImage: Clinical
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/28782489/neural-correlates-in-patients-with-major-affective-disorders-an-fmri-study
#8
Maurizio Pompili
Brain areas of functional activation during emotional stimuli and their correlations with affective temperaments evaluated using Temperament Evaluation of Memphis, Pisa, Paris and San Diego (TEMPS-A) and hopelessness levels assessed with Beck Hopelessness Scale (BHS) have been investigated. Brain activity in response to emotional stimuli was examined by Nuclear Magnetic Resonance Blood Oxygen Level Dependent (NMR BOLD) signal. Seventeen subjects (mean age ± SD = 57 ± 12), diagnosed with major affective disorders and eighteen healthy controls (HC) (mean age ± SD = 50±11) participated in this study...
August 3, 2017: CNS & Neurological Disorders Drug Targets
https://www.readbyqxmd.com/read/28780063/reorganization-of-language-centers-in-patients-with-brain-tumors-located-in-eloquent-speech-areas-a-pre-and-postoperative-preliminary-fmri-study
#9
Katarzyna Gębska-Kośla, Bartosz Bryszewski, Dariusz J Jaskólski, Jan Fortuniak, Maciej Niewodniczy, Ludomir Stefańczyk, Agata Majos
INTRODUCTION: The aim of this study was to determine in pre- and postsurgical fMRI studies the rearrangement of the Broca's and Wernicke's areas and the lateralization index for these areas in patients with brain tumors located near speech centers. Impact of the surgical treatment on the brain plasticity was evaluated. MATERIALS AND METHODS: Pre- and postoperative fMRI examinations were performed in 10 patients with low grade glial, left-sided brain tumors located close to the Broca's (5 patients) or Wernicke's area (5 patients)...
July 29, 2017: Neurologia i Neurochirurgia Polska
https://www.readbyqxmd.com/read/28774649/the-dynamic-imprint-of-word-learning-on-the-dorsal-language-pathway
#10
María-Ángeles Palomar-García, Ana Sanjuán, Elisenda Bueichekú, Noelia Ventura-Campos, César Ávila
According to Hickok and Poeppel (2007), the acquisition of new vocabulary rests on the dorsal language pathway connecting auditory and motor areas. The present study tested this hypothesis longitudinally by measuring BOLD signal changes during a verbal repetition task and modulation of resting state functional connectivity (rs-FC) in the dorsal stream. Thirty-five healthy participants, divided into trained and control groups, completed fMRI sessions on days 1, 10, and 24. Between days 1 and 10, the trained group learned 84 new pseudowords associated with 84 native words...
July 31, 2017: NeuroImage
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
#11
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/28769835/music-of-the-7ts-predicting-and-decoding-multivoxel-fmri-responses-with-acoustic-schematic-and-categorical-music-features
#12
Michael A Casey
Underlying the experience of listening to music are parallel streams of auditory, categorical, and schematic qualia, whose representations and cortical organization remain largely unresolved. We collected high-field (7T) fMRI data in a music listening task, and analyzed the data using multivariate decoding and stimulus-encoding models. Twenty subjects participated in the experiment, which measured BOLD responses evoked by naturalistic listening to twenty-five music clips from five genres. Our first analysis applied machine classification to the multivoxel patterns that were evoked in temporal cortex...
2017: Frontiers in Psychology
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
#13
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/28746187/research-of-cerebral-activation-in-uygur-speaking-and-chinese-speaking-participants-during-verb-generation-task-with-functional-magnetic-resonance-imaging
#14
COMPARATIVE STUDY
Yanling Xi, Ling Liu, Grace Hao, Zulipinuer Abudusadike, Chunhui Jiang, Junran Zhang, Baolan Wang
The aims are to investigate and compare the activated cerebral regions of Uygur-speaking and Chinese-speaking participants during verb generation task.A total of 31 cases of Uygur and 28 cases of Han healthy volunteers were enrolled. They were requested to take verb generation tasks. Blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) was performed. The fMRI images were collected and activated brain regions were analyzed.In Chinese-speaking participants, the main activated cerebral regions were as follows: the left caudate nucleus, the left occipital gyrus, the left fusiform gyrus, bilateral supplementary motor area (BA8/ 6), the left BA32, left precuneus, the left superior parietal lobule, the left inferior parietal lobule (BA7), the left angular gyrus, the right side of the central gyrus (BA9), the left inferior frontal gyrus triangular section, the right pars opercularis gyri frontalis inferiorista, and bilateral cerebellum...
July 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28742093/neuronal-synchrony-and-the-relation-between-the-blood-oxygen-level-dependent-response-and-the-local-field-potential
#15
Dora Hermes, Mai Nguyen, Jonathan Winawer
The most widespread measures of human brain activity are the blood-oxygen-level dependent (BOLD) signal and surface field potential. Prior studies report a variety of relationships between these signals. To develop an understanding of how to interpret these signals and the relationship between them, we developed a model of (a) neuronal population responses and (b) transformations from neuronal responses into the functional magnetic resonance imaging (fMRI) BOLD signal and electrocorticographic (ECoG) field potential...
July 2017: PLoS Biology
https://www.readbyqxmd.com/read/28740768/fmri-after-phalloplasty-with-nerve-anastomosis-in-a-trans-man-patient
#16
Roberto Doria-Medina, Åsa Carlsson, Emma H Jönsson, Lars Jönsson, Andri Thorarinsson, Mattias Lidén, Gennaro Selvaggi
We report on a case of a trans-man patient, who underwent penile reconstruction with the use of a radial forearm flap, urethroplasty, vaginectomy and scrotoplasty, insertion of testicle implants, and penile erection implants, similar to previously described methods. One of the requirements for an ideal phalloplasty is the preservation of erogenous sensitivity, which is often demanded by the patients for fulfilling their sexual well-being. For the first time known to us, we use a functional magnetic resonance imaging following radial forearm flap phalloplasty with nerve anastomosis to assess the cortical activation after clitoral stimulation...
June 2017: Plastic and Reconstructive Surgery. Global Open
https://www.readbyqxmd.com/read/28736698/impact-of-automated-ica-based-denoising-of-fmri-data-in-acute-stroke-patients
#17
D Carone, R Licenik, S Suri, L Griffanti, N Filippini, J Kennedy
Different strategies have been developed using Independent Component Analysis (ICA) to automatically de-noise fMRI data, either focusing on removing only certain components (e.g. motion-ICA-AROMA, Pruim et al., 2015a) or using more complex classifiers to remove multiple types of noise components (e.g. FIX, Salimi-Khorshidi et al., 2014 Griffanti et al., 2014). However, denoising data obtained in an acute setting might prove challenging: the presence of multiple noise sources may not allow focused strategies to clean the data enough and the heterogeneity in the data may be so great to critically undermine complex approaches...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28736310/non-bold-contrast-for-laminar-fmri-in-humans-cbf-cbv-and-cmro2
#18
REVIEW
Laurentius Huber, Kâmil Uludağ, Harald E Möller
Functional magnetic resonance imaging (fMRI) using the blood oxygenation level-dependent (BOLD) contrast indirectly probes neuronal activity changes via evoked cerebral blood flow (CBF), cerebral blood volume (CBV) and cerebral metabolic rate of oxygen (CMRO2) changes. The gradient-echo BOLD signal is mostly sensitive to ascending veins in the tissue and to pial veins. Thereby, the achievable spatial specificity to neuronal activation is limited. Furthermore, the non-linear interaction of CBF, CBV and CMRO2 can hamper quantitative interpretations of the BOLD signal across cortical depths with different baseline physiology...
July 20, 2017: NeuroImage
https://www.readbyqxmd.com/read/28734059/localized-reductions-in-resting-state-functional-connectivity-in-children-with-prenatal-alcohol-exposure
#19
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/28733682/modulation-of-water-diffusion-by-activation-induced-neural-cell-swelling-in-aplysia-californica
#20
Yoshifumi Abe, Khieu Van Nguyen, Tomokazu Tsurugizawa, Luisa Ciobanu, Denis Le Bihan
Diffusion functional magnetic resonance imaging (DfMRI) has been proposed as a method for functional neuroimaging studies, as an alternative to blood oxygenation level dependent (BOLD)-fMRI. DfMRI is thought to more directly reflect neural activation, but its exact mechanism remains unclear. It has been hypothesized that the water apparent diffusion coefficient (ADC) decrease observed upon neural activation results from swelling of neurons or neuron parts. To elucidate the origin of the DfMRI response at cellular level we performed diffusion MR microscopy at 17...
July 21, 2017: Scientific Reports
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