Sensitivity of diffusion MRI to perilesional reactive astrogliosis in focal ischemia

Rachel A. Weber, Clifford H. Chan, Xingju Nie, Emily Maggioncalda, Grace Valiulis, Abigail Lauer, Edward S. Hui, Jens H. Jensen (Corresponding Author), De Anna L. Adkins

Research output: Journal article publicationJournal articleAcademic researchpeer-review

2 Citations (Scopus)

Abstract

Reactive astrogliosis is a response to injury in the central nervous system that plays an essential role in inflammation and tissue repair. It is characterized by hypertrophy of astrocytes, alterations in astrocyte gene expression and astrocyte proliferation. Reactive astrogliosis occurs in multiple neuropathologies, including stroke, traumatic brain injury and Alzheimer's disease, and it has been proposed as a possible source of the changes in diffusion magnetic resonance imaging (dMRI) metrics observed with these diseases. In this study, the sensitivity of dMRI to reactive astrogliosis was tested in an animal model of focal acute and subacute ischemia induced by the vasoconstricting peptide, endothelin-1. Reactive astrogliosis in perilesional cortex was quantified by calculating the astrocyte surface density as determined with a glial fibrillary acidic protein (GFAP) antibody, whereas perilesional diffusion changes were measured in vivo with diffusional kurtosis imaging. We found substantial changes in the surface density of GFAP-positive astrocyte processes and modest changes in dMRI metrics in the perilesional motor cortex following stroke. Although there are time point-specific correlations between dMRI and histological measures, there is no definitive evidence for a causal relationship.

Original languageEnglish
Article numbere3717
JournalNMR in Biomedicine
Volume30
Issue number7
DOIs
Publication statusPublished - Jul 2017
Externally publishedYes

Keywords

  • astrogliosis
  • diffusion
  • GFAP
  • imaging
  • ischemia
  • MRI
  • perilesional
  • stereology

ASJC Scopus subject areas

  • Molecular Medicine
  • Radiology Nuclear Medicine and imaging
  • Spectroscopy

Cite this