title: Visualization of Regional Cerebral Blood Flow Dynamics during Cortical Venous Occlusion using Laser Speckle Contrast Imaging in a Rat Model.
abstract: BACKGROUND
  Cerebral venous ischemia (CVI) is a rare but potentially significant complication of neurosurgical procedures. However, it is still unclear how cerebral venous occlusion (VO) affects regional cerebral blood flow (rCBF) dynamics. To elucidate its pathophysiology in detail, we examined the real-time perfusion dynamics during adjacent vein occlusions using laser speckle contrast imaging (LSCI) in a rat 2-vein occlusion model.
  
  
  METHODS
  Two cortical veins were occluded photochemically using rose Bengal dye in 6 male Wistar rats; rCBF was measured in real time with an LSCI before and after VO. Regions of interest were defined between the 2 veins (A) and on the opposite side of the first occluded vein (B) on semi-quantitative pseudocolor images for off-line analysis. Histopathologic evaluation was performed 3 days after the procedure to assess the extent of infarction.
  
  
  RESULTS
  LSCI revealed a stepwise reduction in CBF, with a sudden decrease just after the first vein occlusion (~20%) and a further decrease after the second (~30%). Significant differences were observed between rCBF dynamics within regions of interest A and B (P = .0004). All rats exhibited infarcts in the superficial cerebral cortex histopathologically.
  
  
  CONCLUSIONS
  This is the first report of LSCI specifically applied to the study of CVI. The extensive real-time measurement with high temporal and spatial resolution revealed the stepwise reduction in rCBF during sequential VO and the ensuing infarcts.
authors.affiliation: Department of Neurosurgery, Nara Medical University School of Medicine, Kashihara, Japan. Electronic address: takeshim@naramed-u.ac.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takeshima
authors.affiliation: Department of Neurosurgery, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Miyake
authors.affiliation: Department of Neurosurgery, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Nakagawa
authors.affiliation: Department of Neurosurgery, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Motoyama
authors.affiliation: Department of Neurosurgery, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Young-Su
authors.initials: YS
authors.lastname: Park
authors.affiliation: Department of Neurosurgery, Nara Medical University School of Medicine, Kashihara, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakase
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000098:blood supply; D002550:Cerebral Veins / Q000473:pathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002561:Cerebrovascular Disorders / Q000503:physiopathology*; D003287:Contrast Media / Q000378:metabolism; D004195:Disease Models, Animal; D007091:Image Processing, Computer-Assisted; D017078:Laser-Doppler Flowmetry; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D003287:Contrast Media
keywords: CBF dynamics; cerebral ischemia; cerebral venous ischemia; cortical infarction; laser speckle contrast imaging; regional cerebral blood flow