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BOLD Mri

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https://www.readbyqxmd.com/read/27911950/a-specialized-multi-transmit-head-coil-for-high-resolution-fmri-of-the-human-visual-cortex-at-7t
#1
Shubharthi Sengupta, Alard Roebroeck, Valentin G Kemper, Benedikt A Poser, Jan Zimmermann, Rainer Goebel, Gregor Adriany
PURPOSE: To design, construct and validate radiofrequency (RF) transmit and receive phased array coils for high-resolution visual cortex imaging at 7 Tesla. METHODS: A 4 channel transmit and 16 channel receive array was constructed on a conformal polycarbonate former. Transmit field efficiency and homogeneity were simulated and validated, along with the Specific Absorption Rate, using [Formula: see text] mapping techniques and electromagnetic simulations. Receiver signal-to-noise ratio (SNR), temporal SNR (tSNR) across EPI time series, g-factors for accelerated imaging and noise correlations were evaluated and compared with a commercial 32 channel whole head coil...
2016: PloS One
https://www.readbyqxmd.com/read/27907094/continuous-descending-modulation-of-the-spinal-cord-revealed-by-functional-mri
#2
Patrick W Stroman, Rachael L Bosma, Andreea I Cotoi, Roxanne H Leung, Jennifer Kornelsen, Jane M Lawrence-Dewar, Caroline F Pukall, Roland Staud
Spontaneous variations in spinal cord activity may arise from regulation of any of a number of functions including sensory, motor, and autonomic control. Here, we use functional MRI (fMRI) of healthy participants to identify properties of blood oxygenation-level dependent (BOLD) variations in the spinal cord in response to knowledge that either a noxious stimulus is impending, or that no stimulus is to be expected. Expectation of a noxious stimulus, or no stimulus, is shown to have a significant effect on wide-spread BOLD signal variations in the spinal cord over the entire time period of the fMRI acquisition...
2016: PloS One
https://www.readbyqxmd.com/read/27898057/functional-brain-mapping-using-specific-sensory-circuit-stimulation-and-a-theoretical-graph-network-analysis-in-mice-with-neuropathic-allodynia
#3
Yuji Komaki, Keigo Hikishima, Shinsuke Shibata, Tsunehiko Konomi, Fumiko Seki, Masayuki Yamada, Naoyuki Miyasaka, Kanehiro Fujiyoshi, Hirotaka J Okano, Masaya Nakamura, Hideyuki Okano
Allodynia, a form of neuropathic pain, is defined as pain in response to a non-nociceptive stimulus. The brain regions responsible for pain, which are not normally activated, can be activated in allodynic mice by providing a suitable stimulus to Aβ-fibers, which transmit signals from tactile sensory fibers. Functional MRI (fMRI) can be used to objectively observe abnormal brain activation. In the present study, fMRI was conducted to investigate allodynia in mice; allodynia was generated by surgical injury at the L4 spinal nerve root, thus selectively stimulating sensory nerve fibers...
November 29, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27888058/cerebrovascular-reactivity-mapping-without-gas-challenges
#4
Peiying Liu, Yang Li, Marco Pinho, Denise C Park, Babu G Welch, Hanzhang Lu
Cerebrovascular reactivity (CVR), the ability of cerebral vessels to dilate or constrict, has been shown to provide valuable information in the diagnosis and treatment evaluation of patients with various cerebrovascular conditions. CVR mapping is typically performed using hypercapnic gas inhalation as a vasoactive challenge while collecting BOLD images, but the inherent need of gas inhalation and the associated apparatus setup present a practical obstacle in applying it in routine clinical use. Therefore, we aimed to develop a new method to map CVR using resting-state BOLD data without the need of gas inhalation...
November 22, 2016: NeuroImage
https://www.readbyqxmd.com/read/27883015/mr-vascular-fingerprinting-in-stroke-and-brain-tumors-models
#5
B Lemasson, N Pannetier, N Coquery, Ligia S B Boisserand, Nora Collomb, N Schuff, M Moseley, G Zaharchuk, E L Barbier, T Christen
In this study, we evaluated an MRI fingerprinting approach (MRvF) designed to provide high-resolution parametric maps of the microvascular architecture (i.e., blood volume fraction, vessel diameter) and function (blood oxygenation) simultaneously. The method was tested in rats (n = 115), divided in 3 models: brain tumors (9 L, C6, F98), permanent stroke, and a control group of healthy animals. We showed that fingerprinting can robustly distinguish between healthy and pathological brain tissues with different behaviors in tumor and stroke models...
November 24, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27881393/food-portion-size-and-energy-density-evoke-different-patterns-of-brain-activation-in-children
#6
Laural K English, S Nicole Fearnbach, Stephen J Wilson, Jennifer O Fisher, Jennifer S Savage, Barbara J Rolls, Kathleen L Keller
BACKGROUND: Large portions of food promote intake, but the mechanisms that drive this effect are unclear. Previous neuroimaging studies have identified the brain-reward and decision-making systems that are involved in the response to the energy density (ED) (kilocalories per gram) of foods, but few studies have examined the brain response to the food portion size (PS). OBJECTIVE: We used functional MRI (fMRI) to determine the brain response to food images that differed in PSs (large and small) and ED (high and low)...
November 23, 2016: American Journal of Clinical Nutrition
https://www.readbyqxmd.com/read/27870414/sex-differences-in-neural-responses-to-subliminal-sad-and-happy-faces-in-healthy-individuals-implications-for-depression
#7
Teresa A Victor, Wayne C Drevets, Masaya Misaki, Jerzy Bodurka, Jonathan Savitz
Twice as many women as men suffer from mood and anxiety disorders, yet the biological underpinnings of this phenomenon have been understudied and remain unclear. We and others have shown that the hemodynamic response to subliminally presented sad or happy faces during functional MRI (fMRI) is a robust biomarker for the attentional bias toward negative information classically observed in major depression. Here we used fMRI to compare the performance of healthy females (n = 28) and healthy males (n = 28) on a backward masking task using a fast event-related design with gradient-recalled, echoplanar imaging with sensitivity encoding...
January 2, 2017: Journal of Neuroscience Research
https://www.readbyqxmd.com/read/27868422/correction-to-dennison-et-al-2016
#8
(no author information available yet)
Reports an error in "Neurobehavioral markers of resilience to depression amongst adolescents exposed to child abuse" by Meg J. Dennison, Margaret A. Sheridan, Daniel S. Busso, Jessica L. Jenness, Matthew Peverill, Maya L. Rosen and Katie A. McLaughlin (Journal of Abnormal Psychology, 2016[Nov], Vol 125[8], 1201-1212). In the original record, there was an error in the title. The word "Adolescents" was singular. The online version of this article has been corrected.(The following abstract of the original article appeared in record 2016-52992-014...
November 17, 2016: Journal of Abnormal Psychology
https://www.readbyqxmd.com/read/27857679/bold-imaging-in-awake-wild-type-and-mu-opioid-receptor-knock-out-mice-reveals-on-target-activation-maps-in-response-to-oxycodone
#9
Kelsey Moore, Dan Madularu, Sade Iriah, Jason R Yee, Praveen Kulkarni, Emmanuel Darcq, Brigitte L Kieffer, Craig F Ferris
Blood oxygen level dependent (BOLD) imaging in awake mice was used to identify differences in brain activity between wild-type, and Mu (μ) opioid receptor knock-outs (MuKO) in response to oxycodone (OXY). Using a segmented, annotated MRI mouse atlas and computational analysis, patterns of integrated positive and negative BOLD activity were identified across 122 brain areas. The pattern of positive BOLD showed enhanced activation across the brain in WT mice within 15 min of intraperitoneal administration of 2...
2016: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/27845359/characterizing-the-blood-oxygen-level-dependent-fluctuations-in-musculoskeletal-tumours-using-functional-magnetic-resonance-imaging
#10
Li-Sha Duan, Meng-Jun Wang, Feng Sun, Zhen-Jiang Zhao, Mei Xing, Yu-Feng Zang, Steven Louis, Sheng-Jie Cui, Jian-Ling Cui, Han Zhang
This study characterized the blood oxygen level-dependent (BOLD) fluctuations in benign and malignant musculoskeletal tumours via power spectrum analyses in pre-established low-frequency bands. BOLD MRI and T1-weighted imaging (T1WI) were collected for 52 patients with musculoskeletal tumours. Three ROIs were drawn on the T1WI image in the tumours' central regions, peripheral regions and neighbouring tissue. The power spectrum of the BOLD within each ROI was calculated and divided into the following four frequency bands: 0...
November 15, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27845256/prospective-motion-correction-in-functional-mri
#11
Maxim Zaitsev, Burak Akin, Pierre LeVan, Benjamin R Knowles
Due to the intrinsic low sensitivity of BOLD-fMRI long scanning is required. Subject motion during fMRI scans reduces statistical significance of the activation maps and increases the prevalence of false activations. Motion correction is therefore an essential tool for a successful fMRI data analysis. Retrospective motion correction techniques are now commonplace and are incorporated into a wide range of fMRI analysis toolboxes. These techniques are advantageous due to robustness, sequence independence and have minimal impact on the fMRI study setup...
November 11, 2016: NeuroImage
https://www.readbyqxmd.com/read/27819477/neurobehavioral-markers-of-resilience-to-depression-amongst-adolescent-exposed-to-child-abuse
#12
Meg J Dennison, Margaret A Sheridan, Daniel S Busso, Jessica L Jenness, Matthew Peverill, Maya L Rosen, Katie A McLaughlin
Childhood maltreatment is strongly associated with depression, which is characterized by reduced reactivity to reward. Identifying factors that mitigate risk for depression in maltreated children is important for understanding etiological links between maltreatment and depression as well as improving early intervention and prevention. We examine whether high reward reactivity at behavioral and neurobiological levels is a marker of resilience to depressive symptomology in adolescence following childhood maltreatment...
November 2016: Journal of Abnormal Psychology
https://www.readbyqxmd.com/read/27807911/effects-of-reduced-oxygen-availability-on-the-vascular-response-and-oxygen-consumption-of-the-activated-human-visual-cortex
#13
Felipe Rodrigues Barreto, Silvia Mangia, Carlos Ernesto Garrido Salmon
PURPOSE: To identify the impact of reduced oxygen availability on the evoked vascular response upon visual stimulation in the healthy human brain by magnetic resonance imaging (MRI). MATERIALS AND METHODS: Functional MRI techniques based on arterial spin labeling (ASL), blood oxygenation level-dependent (BOLD), and vascular space occupancy (VASO)-dependent contrasts were utilized to quantify the BOLD signal, cerebral blood flow (CBF), and volume (CBV) from nine subjects at 3T (7M/2F, 27...
November 3, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27805423/the-potential-of-multiparametric-mri-of-the-breast
#14
Katja Pinker, Thomas H Helbich, Elizabeth A Morris
Magnetic resonance imaging (MRI) is an essential tool in breast imaging, with multiple established indications. Dynamic contrast-enhanced MRI (DCE-MRI) is the backbone of any breast MRI protocol and has an excellent sensitivity and good specificity for breast cancer diagnosis. DCE-MRI provides high-resolution morphological information, as well as some functional information about neo-angiogenesis as a tumour-specific feature. To overcome limitations in specificity, several other functional MRI parameters have been investigated and the application of these combined parameters is defined as multiparametric MRI (mpMRI) of the breast...
November 2, 2016: British Journal of Radiology
https://www.readbyqxmd.com/read/27798357/muscle-oxygenation-during-dynamic-plantar-flexion-exercise-combining-bold-mri-with-traditional-physiological-measurements
#15
Matthew D Muller, Zhijun Li, Christopher T Sica, J Carter Luck, Zhaohui Gao, Cheryl A Blaha, Aimee E Cauffman, Amanda J Ross, Nathan J R Winkler, Michael D Herr, Kristen Brandt, Jianli Wang, David C Gallagher, Prasanna Karunanayaka, Jeffrey Vesek, Urs A Leuenberger, Qing X Yang, Lawrence I Sinoway
Blood-oxygen-level-dependent magnetic resonance imaging (BOLD MRI) has the potential to quantify skeletal muscle oxygenation with high temporal and high spatial resolution. The purpose of this study was to characterize skeletal muscle BOLD responses during steady-state plantar flexion exercise (i.e., during the brief rest periods between muscle contraction). We used three different imaging modalities (ultrasound of the popliteal artery, BOLD MRI, and near-infrared spectroscopy [NIRS]) and two different exercise intensities (2 and 6 kg)...
October 2016: Physiological Reports
https://www.readbyqxmd.com/read/27798200/reduction-of-cortical-oxygenation-in-chronic-kidney-disease-evidence-obtained-with-a-new-analysis-method-of-blood-oxygenation-level-dependent-magnetic-resonance-imaging
#16
Bastien Milani, Annalisa Ansaloni, Sofia Sousa-Guimaraes, Nima Vakilzadeh, Maciej Piskunowicz, Bruno Vogt, Matthias Stuber, Michel Burnier, Menno Pruijm
BACKGROUND: Determinations of renal oxygenation by blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) in chronic kidney disease (CKD) patients have given heterogeneous results, possibly due to the lack of a reproducible method to analyse BOLD-MRI. It therefore remains uncertain whether patients with CKD have a reduced renal tissue oxygenation. We developed a new method to analyse BOLD-MRI signals and applied it to CKD patients and controls. METHODS: MRI was performed under standardized conditions before and 15 min after IV furosemide in 104 CKD patients, 61 hypertensives and 42 controls...
October 17, 2016: Nephrology, Dialysis, Transplantation
https://www.readbyqxmd.com/read/27783807/cerebral-vasomotor-reactivity-assessment-using-transcranial-doppler-and-mri-with-apnea-test
#17
C R Campos Herrera, G C Beltramini, W M Avelar, F O Lima, L M Li
Differently from previous studies that used Transcranial Doppler (TCD) and functional MRI (fMRI) for cerebral vasomotor reactivity (CVR) assessment in patients with carotid stenosis (CS), we assessed CVR using an identical stimulus, the Breath-Holding Test (BHT). We included 15 patients with CS and 7 age-matched controls to verify whether fMRI responded differently to BHT between groups and to calculate the agreement rate between tests. For TCD, impaired CVR was defined when the mean percentage increase on middle cerebral artery velocities was ≤31% on 3 consecutive 30-s apnea intercalated by 4-min normal breathing intervals...
October 24, 2016: Brazilian Journal of Medical and Biological Research, Revista Brasileira de Pesquisas Médicas e Biológicas
https://www.readbyqxmd.com/read/27781035/decoding-the-semantic-content-of-natural-movies-from-human-brain-activity
#18
Alexander G Huth, Tyler Lee, Shinji Nishimoto, Natalia Y Bilenko, An T Vu, Jack L Gallant
One crucial test for any quantitative model of the brain is to show that the model can be used to accurately decode information from evoked brain activity. Several recent neuroimaging studies have decoded the structure or semantic content of static visual images from human brain activity. Here we present a decoding algorithm that makes it possible to decode detailed information about the object and action categories present in natural movies from human brain activity signals measured by functional MRI. Decoding is accomplished using a hierarchical logistic regression (HLR) model that is based on labels that were manually assigned from the WordNet semantic taxonomy...
2016: Frontiers in Systems Neuroscience
https://www.readbyqxmd.com/read/27780207/visual-bold-response-in-late-blind-subjects-with-argus-ii-retinal-prosthesis
#19
E Castaldi, G M Cicchini, L Cinelli, L Biagi, S Rizzo, M C Morrone
Retinal prosthesis technologies require that the visual system downstream of the retinal circuitry be capable of transmitting and elaborating visual signals. We studied the capability of plastic remodeling in late blind subjects implanted with the Argus II Retinal Prosthesis with psychophysics and functional MRI (fMRI). After surgery, six out of seven retinitis pigmentosa (RP) blind subjects were able to detect high-contrast stimuli using the prosthetic implant. However, direction discrimination to contrast modulated stimuli remained at chance level in all of them...
October 2016: PLoS Biology
https://www.readbyqxmd.com/read/27779778/cold-pressor-gel-test-a-safe-alternative-to-the-cold-pressor-test-in-fmri
#20
Maryna Lapotka, María Ruz, Alberto Salamanca Ballesteros, Olga Ocón Hernández
PURPOSE: This study describes a new methodology-the cold pressor gel test (CPGT)-for delivering an accessible experimental pain stimulus, which is reproducible and safe for functional MRI (fMRI). METHODS: The cold pressor test was modified to put safety precautions into the CPGT. The material used is cool gelled water with a thickening product, which provides a stable temperature at 0.2 °C. Thirteen women with chronic pelvic pain were scanned using a 3 Tesla (T) MR scanner equipped with a 12-channel head coil...
October 25, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
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