title: Magnetic resonance imaging as a surrogate measure for histological sub-chronic endpoint in a neonatal rat stroke model.
abstract: BACKGROUND
  It is becoming increasingly recognized that CNS immaturity at birth affects ischemic injury and recovery, and that the consequences of neonatal stroke need to be studied using age-appropriate focal stroke models. The inclusion of magnetic resonance imaging (MRI) as a surrogate measure of stroke progression has provided useful information in adult models, but the benefit for neonatal stroke studies is yet to be established.
  
  
  METHODS
  Postnatal 7-day (P7) rats were subjected to a 3-h transient occlusion of the middle cerebral artery (MCA) which was produced either by inserting a filament via the external carotid artery or via the internal carotid artery. MRI was used to delineate the size and pattern of injury acutely, during MCA occlusion, and 7 days following reperfusion.
  
  
  RESULTS
  The size of the diffusion-weighted (DW) MRI-detectable injury during MCA occlusion was similar following both surgical procedures and resulted in histological lesions 7 days later in all animals. The extent of spontaneous recovery in individual animals varied substantially 7 days later within each group, as was depicted by a combination of DW- and T2W-MRI and confirmed by the corresponding histology.
  
  
  CONCLUSIONS
  The ability of MRI to provide accurate information on the size of histological outcome at 7 days after neonatal focal transient ischemia suggests that MRI is useful as an intermediate surrogate measure of injury progression in long-term neonatal stroke studies.
authors.affiliation: Department of Neurosurgery, University of California, San Francisco, CA 94143, USA.
authors.forename: Nikita
authors.initials: N
authors.lastname: Derugin
authors.forename: Andra
authors.initials: A
authors.lastname: Dingman
authors.forename: Michael F
authors.initials: MF
authors.lastname: Wendland
authors.forename: Christine
authors.initials: C
authors.lastname: Fox
authors.forename: Andy
authors.initials: A
authors.lastname: Bollen
authors.forename: Zinaida S
authors.initials: ZS
authors.lastname: Vexler
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D004578:Electron Spin Resonance Spectroscopy; D005260:Female; D005455:Fluorescent Antibody Technique; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology; D008279:Magnetic Resonance Imaging; D051381:Rats; D017207:Rats, Sprague-Dawley; D020521:Stroke / Q000473:pathology*
chemical_list: D005904:Glial Fibrillary Acidic Protein