title: Magnetic resonance imaging of local and remote vascular remodelling after experimental stroke.
abstract: The pattern of vascular remodelling in relation to recovery after stroke remains largely unclear. We used steady-state contrast-enhanced magnetic resonance imaging to assess the development of cerebral blood volume and microvascular density in perilesional and exofocal areas from (sub)acutely to chronically after transient stroke in rats. Microvascular density was verified histologically after infusion with Evans Blue dye. At day 1, microvascular cerebral blood volume and microvascular density were reduced in and around the ischemic lesion (intralesional borderzone: microvascular cerebral blood volume = 72 ± 8%; microvascular density = 76 ± 8%) (P < 0.05), while total cerebral blood volume remained relatively unchanged. Perilesional microvascular cerebral blood volume and microvascular density subsequently normalized (day 7) and remained relatively stable (day 70). In remote ipsilateral areas in the thalamus and substantia nigra - not part of the ischemic lesion - microvascular density gradually increased between days 1 and 70 (thalamic ventral posterior nucleus: microvascular density = 119 ± 9%; substantia nigra: microvascular density = 122 ± 8% (P < 0.05)), which was confirmed histologically. Our data indicate that initial microvascular collapse, with maintained collateral flow in larger vessels, is followed by dynamic revascularization in perilesional tissue. Furthermore, progressive neovascularization in non-ischemic connected areas may offset secondary neuronal degeneration and/or contribute to non-neuronal tissue remodelling. The complex spatiotemporal pattern of vascular remodelling, involving regions outside the lesion territory, may be a critical endogenous process to promote post-stroke brain reorganization.
authors: 1 Biomedical MR Imaging and Spectroscopy Group, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Pavel
authors: P
authors: Yanev
authors: 1 Biomedical MR Imaging and Spectroscopy Group, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Peter R
authors: PR
authors: Seevinck
authors: 1 Biomedical MR Imaging and Spectroscopy Group, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Umesh S
authors: US
authors: Rudrapatna
authors: 1 Biomedical MR Imaging and Spectroscopy Group, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Mark Jrj
authors: MJ
authors: Bouts
authors: 1 Biomedical MR Imaging and Spectroscopy Group, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Annette
authors: A
authors: van der Toorn
authors: 2 Department of Neurology, Charité - Universitaetsmedizin Berlin, Berlin, Germany.|3 Center for Stroke Research Berlin, Charité - Universitaetsmedizin Berlin, Berlin, Germany.
authors: Karen
authors: K
authors: Gertz
authors: 2 Department of Neurology, Charité - Universitaetsmedizin Berlin, Berlin, Germany.|4 German Center for Cardiovascular Research (DZHK), Universitaetsmedizin Berlin, Berlin, Germany.
authors: Golo
authors: G
authors: Kronenberg
authors: 2 Department of Neurology, Charité - Universitaetsmedizin Berlin, Berlin, Germany.|3 Center for Stroke Research Berlin, Charité - Universitaetsmedizin Berlin, Berlin, Germany.|4 German Center for Cardiovascular Research (DZHK), Universitaetsmedizin Berlin, Berlin, Germany.|5 German Center for Neurodegenerative Diseases (DZNE), Universitaetsmedizin Berlin, Berlin, Germany.|6 Berlin Institute of Health (BIH), Berlin, Germany.
authors: Matthias
authors: M
authors: Endres
authors: 1 Biomedical MR Imaging and Spectroscopy Group, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Geralda A
authors: GA
authors: van Tilborg
authors: 1 Biomedical MR Imaging and Spectroscopy Group, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Rick M
authors: RM
authors: Dijkhuizen
mesh_terms: D000208:Acute Disease; D000818:Animals; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation / Q000502:physiology; D002908:Chronic Disease; D004195:Disease Models, Animal; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D055806:Microvessels / Q000000981:diagnostic imaging / Q000503:physiopathology; D018919:Neovascularization, Physiologic; D017208:Rats, Wistar; D020521:Stroke / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D013378:Substantia Nigra / Q000000981:diagnostic imaging / Q000503:physiopathology; D013788:Thalamus / Q000000981:diagnostic imaging / Q000503:physiopathology; D066253:Vascular Remodeling / Q000502:physiology*
keywords: Angiogenesis; magnetic resonance imaging; stroke recovery; substantia nigra; thalamus