title: Longitudinal diffusion changes in cerebral hemispheres after MCA infarcts.
abstract: Diffusion tensor imaging can be used in vivo to assess the longitudinal and regional microstructural changes occurring after middle cerebral artery (MCA) infarcts in humans. Nine patients were investigated 1 week (D7), 1 (M1), 3 (M3), and 6 months (M6) after the occurrence of an isolated MCA infarction. First, an overall analysis was performed using histograms of mean diffusivity (MD) and fractional anisotropy (FA) in each hemisphere. Thereafter, the regional pattern of diffusion changes was investigated voxel by voxel with statistical parametric mapping 99. In the hemisphere ipsilateral to the infarction, histogram analysis revealed a significant decrease in FA between D7 and M6 associated with a progressive increase in MD from D7 to M3. Remote from the MCA territory, the voxel by voxel analyses detected a significant increase in MD within the thalamus at M3 and M6 and a reduction in FA along the pyramidal tract at M6. In the contralateral hemisphere, between D7 and M6, a significant hemispheric atrophy was observed in association with a global reduction in anisotropy, in the absence of distinctive regional diffusion changes. These results suggest that micro- and macrostructural tissue modifications can be detected with diffusion tensor imaging in regions remote from the ischemic area in both hemispheres.
authors.affiliation: Department of Neurology, CHU Lariboisière, Université Paris VII, Paris, France.
authors.forename: Frédérique
authors.initials: F
authors.lastname: Buffon
authors.forename: Nicolas
authors.initials: N
authors.lastname: Molko
authors.forename: Dominique
authors.initials: D
authors.lastname: Hervé
authors.forename: Raphaël
authors.initials: R
authors.lastname: Porcher
authors.forename: Isabelle
authors.initials: I
authors.lastname: Denghien
authors.forename: Sabina
authors.initials: S
authors.lastname: Pappata
authors.forename: Denis
authors.initials: D
authors.lastname: Le Bihan
authors.forename: Marie-Germaine
authors.initials: MG
authors.lastname: Bousser
authors.forename: Hugues
authors.initials: H
authors.lastname: Chabriat
mesh_terms: D000328:Adult; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D018450:Disease Progression; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000473:pathology*; D008875:Middle Aged; D011859:Radiography; D013687:Telencephalon / Q000000981:diagnostic imaging / Q000473:pathology*; D013997:Time Factors