Investigation of white matter and grey matter alteration in the monkey brain following ischemic stroke by using diffusion tensor imaging.

• Type of Material: Article
• Authors: Chun-Xia Li, Emory University; Yuguang Meng, Emory University; Yumei Yan, Emory University; Doty Kempf, Emory University; Leonard Howell, Emory University; Frank Tong, Emory University; Xiaodong Zhang, Emory University
• Language: English
• Date: 2022-12
• Publisher: iMRI
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2022 Korean Society of Magnetic Resonance in Medicine
• License: Creative Commons Attribution-NonCommercial 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.13104/imri.2022.26.4.275
• Title of Journal or Parent Work: Investig Magn Reson Imaging
• Volume: 26
• Issue: 4
• Start Page: 275
• End Page: 283
• Grant/Funding Information: National Center for Research Resources P51RR000165; Office of Research Infrastructure Programs OD P51OD011132
• Keywords: axial diffusivity; DTI; radial diffusivity; hyper acute stroke; non-human primate

Abstract

BACKGROUND: Investigation of stroke lesion has mostly focused on grey matter (GM) in previous studies and white matter (WM) degeneration during acute stroke is understudied. In the present study, monkeys were utilized to investigate the alterations of GM and WM in the brain following ischemic occlusion using diffusion tensor imaging (DTI). METHODS: Permanent middle cerebral artery occlusion (pMCAO) was induced in rhesus monkeys (n=6) with an interventional approach. Serial DTI was conducted on a clinical 3T in the hyperacute phase (2-6 hours), 48, and 96 hours post occlusion. Regions of interest in GM and WM of lesion areas were selected for data analysis. RESULTS: Mean diffusivity (MD), radial diffusivity (RD), and axial Diffusivity (AD) in WM decreased substantially during hyperacute stroke, as similar as those seen in GM. No obvious fractional anasotropy (FA) changes were seen in GM and WM during hyper acute phase. until 48 hours post stroke when significant fiber losses were oberved also. Pseudo-normalization of MD, AD, and RD was seen at 96 hours. Pathological changes of WM and GM were observed in ischemic areas at 8, 48, and 96 hours post stroke. Relative changes of MD, AD and RD of WM were correlated negatively with infarction volumes at 6 hours post stroke. CONCLUSION: The present study revealed the microstructural changes in gray matter and white matter of monkey brains during acute stroke by using DTI. The preliminary results suggest axial and radial diffusivity (AD and RD) may be sensitive surrogate markers to assess specific microstructural changes in white matter during hyper-acute stroke.