title: Diffusional kurtosis and diffusion tensor imaging reveal different time-sensitive stroke-induced microstructural changes.
abstract: OBJECTIVE
  Diffusion MRI is a promising, clinically feasible imaging technique commonly used to describe white matter changes after stroke. We investigated the sensitivity of diffusion MRI to detect microstructural alterations in gray matter after sensorimotor cortex stroke in adult male rats.
  
  
  METHODS
  The mean diffusivity (MD) and mean kurtosis of perilesional motor cortex were compared with measures in the contralesional forelimb area of sensorimotor cortex at 2 hours, 24 hours, 72 hours, or 25 days after surgery. MD and mean kurtosis were correlated to the surface densities of glia, dendrites, and axons.
  
  
  RESULTS
  Perilesional mean kurtosis was increased at 72 hours and 25 days after stroke, whereas MD was no longer different from contralesional sensorimotor cortex at 24 hours after stroke. There was a significant increase in the density of glial processes at 72 hours after stroke in perilesional motor cortex, which correlated with perilesional MD.
  
  
  CONCLUSIONS
  These data support that mean kurtosis and MD provide different but complimentary information on acute and chronic changes in perilesional cortex. Glia infiltration is associated with pseudonormalization of MD in the perilesional motor cortex at 72 hours after lesion; however, this association is absent 25 days after lesion. These data suggest that there are likely several different, time-specific microstructural changes underlying these 2 complimentary diffusion measures.
authors.affiliation: From the Department of Neurosciences (R.A.W., M.F.F., J.A.H., D.L.A.), Center for Biomedical Imaging (J.H.J., X.N., M.F.F., J.A.H., D.L.A.), Department of Radiology and Radiological Science (J.H.J., X.N., M.F.F., J.A.H.), and Health Sciences and Research, College of Health Professions (D.L.A.), Medical University of South Carolina, Charleston; and Department of Diagnostic Radiology, University of Hong Kong, Pokfulam, Hong Kong (E.S.H.).
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Weber
authors.affiliation: From the Department of Neurosciences (R.A.W., M.F.F., J.A.H., D.L.A.), Center for Biomedical Imaging (J.H.J., X.N., M.F.F., J.A.H., D.L.A.), Department of Radiology and Radiological Science (J.H.J., X.N., M.F.F., J.A.H.), and Health Sciences and Research, College of Health Professions (D.L.A.), Medical University of South Carolina, Charleston; and Department of Diagnostic Radiology, University of Hong Kong, Pokfulam, Hong Kong (E.S.H.).
authors.forename: Edward S
authors.initials: ES
authors.lastname: Hui
authors.affiliation: From the Department of Neurosciences (R.A.W., M.F.F., J.A.H., D.L.A.), Center for Biomedical Imaging (J.H.J., X.N., M.F.F., J.A.H., D.L.A.), Department of Radiology and Radiological Science (J.H.J., X.N., M.F.F., J.A.H.), and Health Sciences and Research, College of Health Professions (D.L.A.), Medical University of South Carolina, Charleston; and Department of Diagnostic Radiology, University of Hong Kong, Pokfulam, Hong Kong (E.S.H.).
authors.forename: Jens H
authors.initials: JH
authors.lastname: Jensen
authors.affiliation: From the Department of Neurosciences (R.A.W., M.F.F., J.A.H., D.L.A.), Center for Biomedical Imaging (J.H.J., X.N., M.F.F., J.A.H., D.L.A.), Department of Radiology and Radiological Science (J.H.J., X.N., M.F.F., J.A.H.), and Health Sciences and Research, College of Health Professions (D.L.A.), Medical University of South Carolina, Charleston; and Department of Diagnostic Radiology, University of Hong Kong, Pokfulam, Hong Kong (E.S.H.).
authors.forename: Xingju
authors.initials: X
authors.lastname: Nie
authors.affiliation: From the Department of Neurosciences (R.A.W., M.F.F., J.A.H., D.L.A.), Center for Biomedical Imaging (J.H.J., X.N., M.F.F., J.A.H., D.L.A.), Department of Radiology and Radiological Science (J.H.J., X.N., M.F.F., J.A.H.), and Health Sciences and Research, College of Health Professions (D.L.A.), Medical University of South Carolina, Charleston; and Department of Diagnostic Radiology, University of Hong Kong, Pokfulam, Hong Kong (E.S.H.).
authors.forename: Maria F
authors.initials: MF
authors.lastname: Falangola
authors.affiliation: From the Department of Neurosciences (R.A.W., M.F.F., J.A.H., D.L.A.), Center for Biomedical Imaging (J.H.J., X.N., M.F.F., J.A.H., D.L.A.), Department of Radiology and Radiological Science (J.H.J., X.N., M.F.F., J.A.H.), and Health Sciences and Research, College of Health Professions (D.L.A.), Medical University of South Carolina, Charleston; and Department of Diagnostic Radiology, University of Hong Kong, Pokfulam, Hong Kong (E.S.H.).
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Helpern
authors.affiliation: From the Department of Neurosciences (R.A.W., M.F.F., J.A.H., D.L.A.), Center for Biomedical Imaging (J.H.J., X.N., M.F.F., J.A.H., D.L.A.), Department of Radiology and Radiological Science (J.H.J., X.N., M.F.F., J.A.H.), and Health Sciences and Research, College of Health Professions (D.L.A.), Medical University of South Carolina, Charleston; and Department of Diagnostic Radiology, University of Hong Kong, Pokfulam, Hong Kong (E.S.H.). adkinsdl@musc.edu.
authors.forename: DeAnna L
authors.initials: DL
authors.lastname: Adkins
mesh_terms: D000818:Animals; D056324:Diffusion Tensor Imaging / Q000379:methods*; D066128:Gray Matter / Q000378:metabolism / Q000473:pathology*; D008297:Male; D051381:Rats; D020318:Rats, Long-Evans; D066191:Sensorimotor Cortex / Q000378:metabolism / Q000473:pathology*; D020521:Stroke / Q000378:metabolism / Q000473:pathology*; D013997:Time Factors
keywords: diffusion tensor imaging; glial fibrillary acidic protein; ischemia; motor cortex; stroke