0000000000408645

AUTHOR

Tony Stoecker

showing 3 related works from this author

Characterizing microstructural tissue properties in multiple sclerosis with diffusion MRI at 7 T and 3 T: The impact of the experimental design

2019

The recent introduction of advanced magnetic resonance (MR) imaging techniques to characterize focal and global degeneration in multiple sclerosis (MS), like the Composite Hindered and Restricted Model of Diffusion, or CHARMED, diffusional kurtosis imaging (DKI) and Neurite Orientation Dispersion and Density Imaging (NODDI) made available new tools to image axonal pathology non-invasively in vivo. These methods already showed greater sensitivity and specificity compared to conventional diffusion tensor-based metrics (e.g., fractional anisotropy), overcoming some of its limitations. While previous studies uncovered global and focal axonal degeneration in MS patients compared to healthy contr…

0301 basic medicineTime FactorsUltra-high field MRIAxonal pathologyCohort Studies0302 clinical medicineNuclear magnetic resonancemethods [Diffusion Magnetic Resonance Imaging]MicrostructureNODDImedicine.diagnostic_testGeneral NeuroscienceWATER DIFFUSIONmedicine.anatomical_structureResearch DesignKurtosisMulti-shell diffusion MRIAxonal degenerationWHITE-MATTERTENSORAdultMaterials sciencetherapy [Multiple Sclerosis]Sensitivity and SpecificityWhite matterMultiple sclerosis03 medical and health sciencesFractional anisotropyImage Interpretation Computer-Assistedmedicinediagnostic imaging [Nerve Degeneration]Journal ArticleHumansddc:610OPTIMIZATIONMultiple sclerosisinstrumentation [Diffusion Magnetic Resonance Imaging]diagnostic imaging [Multiple Sclerosis]Magnetic resonance imagingQUANTIFICATIONmedicine.diseaseMODELPATHOLOGYDiffusion Magnetic Resonance Imaging030104 developmental biologyRESOLUTIONDENSITYNerve Degeneration030217 neurology & neurosurgeryDiffusion MRI
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Epoch versus impulse models in the analysis of parametric fMRI studies

2013

Abstract Objective In parametric fMRI studies the relationship between the amplitude of the hemodynamic response and electrophysiological or behavioral parameters is commonly analyzed using the general linear model (GLM). We examined ways of using single-trial response time (RT) in the analysis of a decision-making task to better isolate task-specific activation. Methods fMRI and RT data were recorded in twenty-one subjects performing a visual-oddball-task. Four explanatory variables (EVs) were generated for the GLM-analysis: A conventional (constant impulse) EV, a constant epoch EV informed using subjects’ average RT, a variable impulse EV and a variable epoch EV both informed using single…

AdultMaleImpulse (physics)Young AdultPhysiology (medical)Attention networkReaction TimeHumansParametric statisticsGeneral linear modelBrain MappingCommunicationSeries (stratigraphy)business.industryConfoundingBrainElectroencephalographyPattern recognitionMiddle AgedMagnetic Resonance ImagingSensory SystemsAmplitudeNeurologyLinear ModelsFemaleNeurology (clinical)Artificial intelligencebusinessPsychologyConstant (mathematics)psychological phenomena and processesClinical Neurophysiology
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Nicotine effects on anterior cingulate cortex in schizophrenia and healthy smokers as revealed by EEG-informed fMRI

2012

Abstract Nicotine can have beneficial effects on attention performance and corresponding brain function in both schizophrenia patients and healthy controls, but it remains controversial whether nicotine affects brain function differentially in patients vs. controls. The effects of nicotine on brain activity elicited by attention-requiring oddball-type tasks have not been studied in schizophrenia patients. In this study we sought to investigate the impact of nicotine on the p300 evoked potential component and corresponding fMRI (functional magnetic resonance imaging) activation measures in schizophrenia patients and controls. Applying a double-blind, placebo-controlled cross-over design, the…

AdultMaleNicotineAdolescentBrain activity and meditationNeuroscience (miscellaneous)ElectroencephalographyGyrus Cingulibehavioral disciplines and activitiesNicotineYoung AdultDouble-Blind MethodImage Processing Computer-AssistedmedicineHumansRadiology Nuclear Medicine and imagingIn patientNicotinic AgonistsEvoked potentialEvoked PotentialsAnterior cingulate cortexAnalysis of Variancemedicine.diagnostic_testSmokingElectroencephalographyMiddle Agedmedicine.diseaseMagnetic Resonance ImagingOxygenPsychiatry and Mental healthmedicine.anatomical_structureSchizophreniaSchizophreniaFemalePsychologyFunctional magnetic resonance imagingNeurosciencemedicine.drugPsychiatry Research: Neuroimaging
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