Publications by authors named "Kevin Epperson"

Objective: Congenital heart disease affects 1% of US births, with many babies requiring major cardiothoracic surgery under cardiopulmonary bypass (CPB), exposing the more critical patients to neurodevelopmental impairment. Optimal surgical parameters to minimize neuronal injury are unknown. We used H MRS and blood ammonia assays in a neonatal pig model of CPB to compare two approaches, complete circulatory arrest (CA) versus antegrade cerebral perfusion (ACP).

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  • Clinical research typically requires careful study designs that account for variables like sex and age, but often overlooks body size factors like height and weight in neuroimaging studies.
  • This study analyzed data from 267 healthy adults to explore how body height and weight relate to various brain and spinal cord MRI metrics, finding significant correlations, especially with brain gray matter volume and cervical spinal cord area.
  • The results suggest that body size is an important biological variable that should be included in clinical neuroimaging study designs to enhance accuracy in understanding brain and spinal cord structures.
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  • A new standardized quantitative MRI protocol for spinal cord imaging, called the spine generic protocol, has been developed to be used with 3T MRI systems from major manufacturers like GE, Philips, and Siemens.
  • The protocol includes specific imaging techniques for evaluating spinal cord macrostructure and microstructure, such as T1 and T2-weighted imaging to determine cross-sectional areas and diffusion-weighted imaging for white matter assessment.
  • An open-access document detailing the protocol is available online, providing a useful resource for researchers and clinicians aiming to enhance spinal cord imaging in neuroimaging practices.
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  • - The paper by Cohen-Adad et al. introduces a standardized MRI protocol for evaluating spinal cord integrity, tested across 19 and 42 centers for single and multi-subject datasets respectively, involving a total of 260 participants.
  • - The datasets are openly available online, allowing researchers to access valuable data for analysis using tools like the Spinal Cord Toolbox, which produces normative values and statistics on variability across sites and manufacturers.
  • - The protocol demonstrated high reproducibility with less than 5% variation across different sites and manufacturers, aiming to enhance the accessibility and reliability of quantitative MRI assessments in spinal research.
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  • The study investigates the impact of different actuation frequencies on brain stiffness measurements obtained through magnetic resonance elastography (MRE), aiming to enhance accuracy in cross-study comparisons.
  • Six healthy volunteers underwent MRE using a specific imaging technique, during which various material models (Maxwell, Kelvin-Voigt, Springpot, and Zener) were analyzed to find the best-fit parameters.
  • Results indicated that optimal frequency combinations (30-60-70 Hz for Zener and 30-40-80 Hz for Springpot models) effectively approximate brain tissue response, paving the way for a refined multifrequency MRE protocol tailored to different brain regions.
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Purpose: To demonstrate and evaluate the scan time and quantitative accuracy of simultaneous bilateral-knee imaging compared with single-knee acquisitions.

Methods: Hardware modifications and safety testing was performed to enable MR imaging with two 16-channel flexible coil arrays. Noise covariance and sensitivity-encoding g-factor maps for the dual-coil-array configuration were computed to evaluate coil cross-talk and noise amplification.

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