Effect of Aging on the Viscoelastic Properties of Hippocampal Subfields Assessed with High-Resolution MR Elastography

Peyton L. Delgorio, Lucy V. Hiscox, Ana M. Daugherty, Faria Sanjana, Ryan T. Pohlig, James M. Ellison, Christopher R. Martens, Hillary Schwarb, Matthew D.J. McGarry, Curtis L. Johnson

Research output: Contribution to journalArticlepeer-review

Abstract

Age-related memory impairments have been linked to differences in structural brain parameters, including the integrity of the hippocampus (HC) and its distinct hippocampal subfields (HCsf). Imaging methods sensitive to the underlying tissue microstructure are valuable in characterizing age-related HCsf structural changes that may relate to cognitive function. Magnetic resonance elastography (MRE) is a noninvasive MRI technique that can quantify tissue viscoelasticity and may provide additional information about aging effects on HCsf health. Here, we report a high-resolution MRE protocol to quantify HCsf viscoelasticity through shear stiffness, μ, and damping ratio, ξ, which reflect the integrity of tissue composition and organization. HCsf exhibit distinct mechanical properties-the subiculum had the lowest μ and both subiculum and entorhinal cortex had the lowest ξ. Both measures correlated with age: HCsf μ was lower with age (P < 0.001) whereas ξ was higher (P = 0.002). The magnitude of age-related differences in ξ varied across HCsf (P = 0.011), suggesting differential patterns of brain aging. This study demonstrates the feasibility of using MRE to assess HCsf microstructural integrity and suggests incorporation of these metrics to evaluate HC health in neurocognitive disorders.

Original languageEnglish
Pages (from-to)2799-2811
Number of pages13
JournalCerebral cortex (New York, N.Y. : 1991)
Volume31
Issue number6
Early online date18 Jan 2021
DOIs
Publication statusPublished - 30 Jun 2021

Keywords

  • aging
  • hippocampus
  • magnetic resonance elastography
  • stiffness
  • viscoelasticity

ASJC Scopus subject areas

  • Cognitive Neuroscience
  • Cellular and Molecular Neuroscience

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