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Deven A Karvelas, Sean D Rundell, Janna L Friedly, Alfred C Gellhorn, Laura S Gold, Bryan A Comstock, Patrick J Heagerty, Brian W Bresnahan, David R Nerenz, Jeffrey G Jarvik
BACKGROUND: The association between early physical therapy (PT) and subsequent healthcare utilization following a new visit for low back pain is not clear, particularly in the setting of acute low back pain. PURPOSE: To estimate the association between initiating early physical therapy following a new visit for an episode of low back pain and subsequent back-pain-specific health care utilization in older adults. STUDY DESIGN/SETTING: Prospective cohort study...
October 17, 2016: Spine Journal: Official Journal of the North American Spine Society
Sami Al Kasab, Michael J Lynn, Tanya N Turan, Colin P Derdeyn, David Fiorella, Bethany F Lane, L Scott Janis, Marc I Chimowitz
BACKGROUND: An American Heart Association/American Stroke Association (AHA/ASA) writing committee has recently recommended that tissue evidence of cerebral infarction associated with temporary symptoms (CITS) lasting <24 hours should be considered a stroke. We analyzed the impact of considering CITS as equivalent to stroke on the results of the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial. METHODS: We compared outcomes in the medical (n = 227) and stenting (n = 224) groups in SAMMPRIS using the following primary end point (new components in bold): any stroke, CITS, or death within 30 days after enrollment or within 30 days after a revascularization procedure for the qualifying lesion during follow-up; or ischemic stroke or CITS in the territory of the qualifying artery beyond 30 days...
October 17, 2016: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
Benedikt Wiestler, Anne Kluge, Mathias Lukas, Jens Gempt, Florian Ringel, Jürgen Schlegel, Bernhard Meyer, Claus Zimmer, Stefan Förster, Thomas Pyka, Christine Preibisch
Non-invasive, imaging-based examination of glioma biology has received increasing attention in the past couple of years. To this end, the development and refinement of novel MRI techniques, reflecting underlying oncogenic processes such as hypoxia or angiogenesis, has greatly benefitted this research area. We have recently established a novel BOLD (blood oxygenation level dependent) based MRI method for the measurement of relative oxygen extraction fraction (rOEF) in glioma patients. In a set of 37 patients with newly diagnosed glioma, we assessed the performance of a machine learning model based on multiple MRI modalities including rOEF and perfusion imaging to predict WHO grade...
October 14, 2016: Scientific Reports
Chiara Sarappa, Elena Salvatore, Alessandro Filla, Sirio Cocozza, Cinzia Valeria Russo, Francesco Saccà, Arturo Brunetti, Giuseppe De Michele, Mario Quarantelli
The fractional Amplitude of Low Frequency Fluctuations (fALFF) and the degree of local synchronization (Regional Homogeneity - ReHo) of resting-state BOLD signal have been suggested to map spontaneous neuronal activity and local functional connectivity, respectively. We compared voxelwise, independent of atrophy, the fALFF and ReHo patterns of 11 presymptomatic (ps-HD) and 28 symptomatic (sHD) Huntington's disease mutation carriers, with those of 40 normal volunteers, and tested their possible correlations with the motor and cognitive subscores of the Unified Huntington's Disease Rating Scale...
October 12, 2016: Brain Imaging and Behavior
Jackie Leung, James Duffin, Joseph A Fisher, Andrea Kassner
OBJECTIVES: Cerebrovascular reactivity (CVR) measures the ability of cerebral blood vessels to change their diameter and, hence, their capacity to regulate regional blood flow in the brain. High resolution quantitative maps of CVR can be produced using blood-oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) in combination with a carbon dioxide stimulus, and these maps have become a useful tool in the clinical evaluation of cerebrovascular disorders. However, conventional CVR analysis does not fully characterize the BOLD response to a stimulus as certain regions of the brain are slower to react to the stimulus than others, especially in disease...
2016: NeuroImage: Clinical
C S Hakkers, J E Arends, R E Barth, S Du Plessis, A I M Hoepelman, M Vink
HIV-associated neurocognitive disorder (HAND) is a frequently occurring comorbidity of HIV infection. Evidence suggests this condition starts subclinical before a progression to a symptomatic stage. Blood oxygenated level dependent (BOLD) fMRI has shown to be a sensitive tool to detect abnormal brain function in an early stage and might therefore be useful to evaluate the effect of HIV infection on brain function. An extensive literature search was performed in June 2015. Eligibility criteria for included studies were as follows: (1) conducting with HIV-positive patients, (2) using BOLD fMRI, and (3) including a HIV-negative control group...
October 7, 2016: Journal of Neurovirology
Neil P Jerome, Jessica K R Boult, Matthew R Orton, James d'Arcy, David J Collins, Martin O Leach, Dow-Mu Koh, Simon P Robinson
BACKGROUND: To investigate the combined use of intravoxel incoherent motion (IVIM) diffusion-weighted (DW) and blood oxygen level dependent (BOLD) magnetic resonance imaging (MRI) to assess rat renal function using a 1.5T clinical platform. METHODS: Multiple b-value DW and BOLD MR images were acquired from adult rats using a parallel clinical coil arrangement, enabling quantitation of the apparent diffusion coefficient (ADC), IVIM-derived diffusion coefficient (D), pseudodiffusion coefficient (D*) and perfusion fraction (f), and the transverse relaxation time T2*, for whole kidney, renal cortex, and medulla...
October 3, 2016: BMC Nephrology
J Sherwood, K Lovas, M Rich, Q Yin, K Lackey, M S Bolding, Y Bao
Recent research efforts about iron oxide nanoparticles has focused on the development of iron oxide-based T1 contrast agents for magnetic resonance imaging (MRI), such as ultrasmall iron oxide nanospheres (USNPs <4 nm) and ultrathin nanowires (NW, diameter <4 nm). In this paper, we report the cellular uptake behaviors of these two types of ultrasmall scale nanostructures on HepG2 cells. Both these two nanostructures were functionalized with tannic acid and their physical and chemical properties were carefully analyzed before cellular tests...
October 14, 2016: Nanoscale
Anna I Blazejewska, Sharmishtaa Seshamani, Susan K McKown, Jason S Caucutt, Manjiri Dighe, Christopher Gatenby, Colin Studholme
PURPOSE: Maximization of the blood oxygen level-dependent (BOLD) functional MRI (fMRI) contrast requires the echo time of the MR sequence to match the T2* value of the tissue of interest, which is expected to be higher in the fetal brain compared with the brain of a child or an adult. METHODS: T2* values of the cortical plate/cortical gray matter tissue in utero in healthy fetuses from mid-gestation onward (20-36 gestational weeks) were measured using 3D T2* maps calculated from 2D dual-echo T2*-weighted data corrected for between-slice motion and reconstructed in 1...
October 3, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Peiying Liu, Babu G Welch, Yang Li, Hong Gu, Darlene King, Yihong Yang, Marco Pinho, Hanzhang Lu
Diagnosis and treatment monitoring of cerebrovascular diseases routinely require hemodynamic imaging of the brain. Current methods either only provide part of the desired information or require the injection of multiple exogenous agents. In this study, we developed a multiparametric imaging scheme for the imaging of brain hemodynamics and function using gas-inhalation MRI. The proposed technique uses a single MRI scan to provide simultaneous measurements of baseline venous cerebral blood volume (vCBV), cerebrovascular reactivity (CVR), bolus arrival time (BAT), and resting-state functional connectivity (fcMRI)...
September 28, 2016: NeuroImage
Leila M Soravia, Ariane Orosz, Simon Schwab, Masahito Nakataki, Roland Wiest, Andrea Federspiel
BACKGROUND: Imaging studies have provided evidence that cognitive-behavioral therapy (CBT) is able to change brain activation in phobic patients in response to threatening stimuli. The changes occurred in both emotion-generating and modulatory regions. In this study, we use a data-driven approach to explore resting state cerebral blood flow (CBF) measured by arterial spin labeling (ASL), before and after CBT. METHODS: Eight female patients with spider phobia were scanned before and 1 month after an exposure-based group therapy for spider phobia...
September 2016: Brain and Behavior
Miriam C Klein-Flügge, Steven W Kennerley, Karl Friston, Sven Bestmann
UNLABELLED: Integrating costs and benefits is crucial for optimal decision-making. Although much is known about decisions that involve outcome-related costs (e.g., delay, risk), many of our choices are attached to actions and require an evaluation of the associated motor costs. Yet how the brain incorporates motor costs into choices remains largely unclear. We used human fMRI during choices involving monetary reward and physical effort to identify brain regions that serve as a choice comparator for effort-reward trade-offs...
September 28, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Jordan E Pierce, Jennifer E McDowell
Cognitive control is engaged to facilitate stimulus-response mappings for novel, complex tasks and supervise performance in unfamiliar, challenging contexts-processes supported by pFC, ACC, and posterior parietal cortex. With repeated task practice, however, the appropriate task set can be selected in a more automatic fashion with less need for top-down cognitive control and weaker activation in these brain regions. One model system for investigating cognitive control is the ocular motor circuitry underlying saccade production, with basic prosaccade trials (look toward a stimulus) and complex antisaccade trials (look to the mirror image location) representing low and high levels of cognitive control, respectively...
September 27, 2016: Journal of Cognitive Neuroscience
Gabriëlla A M Blokland, Angus K Wallace, Narelle K Hansell, Paul M Thompson, Ian B Hickie, Grant W Montgomery, Nicholas G Martin, Katie L McMahon, Greig I de Zubicaray, Margaret J Wright
In a population-based genome-wide association (GWA) study of n-back working memory task-related brain activation, we extracted the average percent BOLD signal change (2-back minus 0-back) from 46 regions-of-interest (ROIs) in functional MRI scans from 863 healthy twins and siblings. ROIs were obtained by creating spheres around group random effects analysis local maxima, and by thresholding a voxel-based heritability map of working memory brain activation at 50%. Quality control for test-retest reliability and heritability of ROI measures yielded 20 reliable (r>0...
September 23, 2016: International Journal of Psychophysiology
Joana R Loureiro, Gisela E Hagberg, Thomas Ethofer, Michael Erb, Jonas Bause, Philipp Ehses, Klaus Scheffler, Marc Himmelbach
The superior colliculus (SC) is a layered structure located in the midbrain. We exploited the improved spatial resolution and BOLD signal strength available at 9.4 T to investigate the depth profile of visual BOLD responses in the human SC based on distortion-corrected EPI data with a 1 mm isotropic resolution. We used high resolution (350 µm in-plane) anatomical images to determine regions-of-interest of the SC and applied a semi-automated method to segment it into superficial, intermediate, and deep zones...
September 23, 2016: Human Brain Mapping
Hironori Kuga, Toshiaki Onitsuka, Yoji Hirano, Itta Nakamura, Naoya Oribe, Hiroaki Mizuhara, Ryota Kanai, Shigenobu Kanba, Takefumi Ueno
Recent MRI studies have shown that schizophrenia is characterized by reductions in brain gray matter, which progress in the acute state of the disease. Cortical circuitry abnormalities in gamma oscillations, such as deficits in the auditory steady state response (ASSR) to gamma frequency (>30-Hz) stimulation, have also been reported in schizophrenia patients. In the current study, we investigated neural responses during click stimulation by BOLD signals. We acquired BOLD responses elicited by click trains of 20, 30, 40 and 80-Hz frequencies from 15 patients with acute episode schizophrenia (AESZ), 14 symptom-severity-matched patients with non-acute episode schizophrenia (NASZ), and 24 healthy controls (HC), assessed via a standard general linear-model-based analysis...
September 13, 2016: EBioMedicine
Isabelle Lajoie, Felipe B Tancredi, Richard D Hoge
The current generation of calibrated MRI methods goes beyond simple localization of task-related responses to allow the mapping of resting-state cerebral metabolic rate of oxygen (CMRO2) in micromolar units and estimation of oxygen extraction fraction (OEF). Prior to the adoption of such techniques in neuroscience research applications, knowledge about the precision and accuracy of absolute estimates of CMRO2 and OEF is crucial and remains unexplored to this day. In this study, we addressed the question of methodological precision by assessing the regional inter-subject variance and intra-subject reproducibility of the BOLD calibration parameter M, OEF, O2 delivery and absolute CMRO2 estimates derived from a state-of-the-art calibrated BOLD technique, the QUantitative O2 (QUO2) approach...
2016: PloS One
Bernd Feige, Kai Spiegelhalder, Andrea Kiemen, Oliver G Bosch, Ludger Tebartz van Elst, Jürgen Hennig, Erich Seifritz, Dieter Riemann
Functional activation as evidenced by blood oxygen level-dependent (BOLD) functional MRI changes or event-related EEG is known to closely follow patterns of stimulation or self-paced action. Any lags are compatible with axonal conduction velocities and neural integration times. The important analysis of resting state networks is generally based on the assumption that these principles also hold for spontaneous fluctuations in brain activity. Previous observations using simultaneous EEG and fMRI indicate that slower processes, with delays in the seconds range, determine at least part of the relationship between spontaneous EEG and fMRI...
September 13, 2016: NeuroImage
Flavia Nelson, Mohammad A Akhtar, Edward Zúñiga, Carlos A Perez, Khader M Hasan, Jeffrey Wilken, Jerry S Wolinsky, Ponnada A Narayana, Joel L Steinberg
BACKGROUND: Cognitive impairment (CI) cannot be diagnosed by magnetic resonance imaging (MRI). Functional magnetic resonance imaging (fMRI) paradigms, such as the immediate/delayed memory task (I/DMT), detect varying degrees of working memory (WM). Preliminary findings using I/DMT showed differences in blood oxygenation level dependent (BOLD) activation between impaired (MSCI, n = 12) and non-impaired (MSNI, n = 9) multiple sclerosis (MS) patients. OBJECTIVES: The aim of the study was to confirm CI detection based on I/DMT BOLD activation in a larger cohort of MS patients...
September 9, 2016: Multiple Sclerosis: Clinical and Laboratory Research
Harshan Ravi, Peiying Liu, Shin-Lei Peng, Hanli Liu, Hanzhang Lu
Hemodynamic mapping using gas inhalation has received increasing interest in recent years. Cerebrovascular reactivity (CVR), which reflects the ability of the brain vasculature to dilate in response to a vasoactive stimulus, can be measured by CO2 inhalation with continuous acquisition of blood oxygen level-dependent (BOLD) magnetic resonance images. Cerebral blood volume (CBV) can be measured by O2 inhalation. These hemodynamic mapping methods are appealing because of their absence of gadolinium contrast agent, their ability to assess both baseline perfusion and vascular reserve, and their utility in calibrating the functional magnetic resonance imaging (fMRI) signal...
November 2016: NMR in Biomedicine
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