High-resolution magnetic resonance elastography reveals differences in subcortical gray matter viscoelasticity between young and healthy older adults

Lucy V Hiscox, Curtis L Johnson, Matthew D J McGarry, Michael Perrins, Aimee Littlejohn, Edwin J R van Beek, Neil Roberts, John M Starr

Research output: Contribution to journalArticlepeer-review

33 Citations (Scopus)

Abstract

Volumetric structural magnetic resonance imaging (MRI) is commonly used to determine the extent of neuronal loss in aging, indicated by cerebral atrophy. The brain, however, exhibits other biophysical characteristics such as mechanical properties, which can be quantified with magnetic resonance elastography (MRE). MRE is an emerging noninvasive imaging technique for measuring viscoelastic tissue properties, proven to be sensitive metrics of neural tissue integrity, as described by shear stiffness, μ and damping ratio, ξ parameters. The study objective was to evaluate global and regional MRE parameter differences between young (19-30 years, n = 12) and healthy older adults (66-73 years, n = 12) and to assess whether MRE measures provide additive value over volumetric magnetic resonance imaging measurements. We investigated the viscoelasticity of the global cerebrum and 6 regions of interest (ROIs) including the amygdala, hippocampus, caudate, pallidum, putamen, and thalamus. In older adults, we found a decrease in μ in all ROIs, except for the hippocampus, indicating widespread brain softening; an effect that remained significant after controlling for ROI volume. In contrast, the relative viscous-to-elastic behavior of the brain ξ did not differ between age groups, suggesting a preservation of the organization of the tissue microstructure. These data support the use of MRE as a novel imaging biomarker for characterizing age-related differences to neural tissue not captured by volumetric imaging alone.

Original languageEnglish
Pages (from-to)158-167
Number of pages10
JournalNeurobiology of Aging
Volume65
Early online date6 Feb 2018
DOIs
Publication statusPublished - 31 May 2018

Keywords

  • Adolescent
  • Adult
  • Aged
  • Cerebrum/anatomy & histology
  • Elasticity
  • Elasticity Imaging Techniques/methods
  • Female
  • Gray Matter/anatomy & histology
  • Healthy Aging/pathology
  • Humans
  • Image Enhancement/methods
  • Male
  • Organ Size
  • Viscosity
  • Young Adult

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