title: Hemodynamic effects of combined focal cerebral ischemia and amyloid protein toxicity in a rat model: a functional CT study.
abstract: OBJECTIVE
  Clinical evidence indicates that cerebral ischemia (CI) and a pathological factor of Alzheimer's disease, the β-amyloid (Aβ) protein, can increase the rate of cognitive impairment in the ageing population. Using the CT Perfusion (CTP) functional imaging, we sought to investigate the interaction between CI and the Aβ protein on cerebral hemodynamics.
  
  
  METHODS
  A previously established rat model of CI and Aβ was used for the CTP study. Iodinated contrast was given intravenously, while serial CT images of sixteen axial slices were acquired. Cerebral blood flow (CBF) and blood volume (CBV) parametric maps were co-registered to a rat brain atlas and regions of interest were drawn on the maps. Microvascular alteration was investigated with histopathology.
  
  
  RESULTS
  CTP results revealed that ipsilateral striatum of Aβ+CI and CI groups showed significantly lower CBF and CBV than control at the acute phase. Striatal CBF and CBV increased significantly at week 1 in the CI and Aβ+CI groups, but not in the Aβ alone or control group. Histopathology showed that average density of dilated microvessels in the ipsilateral striatum in CI and Aβ+CI groups was significantly higher than control at week 1, indicating this could be associated with hyperperfusion and hypervolemia observed from CTP results.
  
  
  CONCLUSIONS
  These results demonstrate that CTP can quantitatively measure the hemodynamic disturbance on CBF and CBV functional maps in a rat model of CI interacting with Aβ.
authors: Imaging Laboratories, Robarts Research Institute, Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada.
authors: Jun
authors: J
authors: Yang
authors: Department of Radiology, Foothills Medical Center, University of Calgary, Calgary, Alberta, Canada.
authors: Christopher D
authors: CD
authors: d'Esterre
authors: Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada.
authors: Zareen
authors: Z
authors: Amtul
authors: Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada.
authors: David F
authors: DF
authors: Cechetto
authors: Imaging Laboratories, Robarts Research Institute, Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada; Imaging Division, Lawson Health Research Institute, London, Ontario, Canada.
authors: Ting Yim
authors: TY
authors: Lee
mesh_terms: D061605:Administration, Intravenous; D058227:Amyloidogenic Proteins / Q000633:toxicity*; D000818:Animals; D001810:Blood Volume / Q000187:drug effects; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging / Q000187:drug effects / Q000503:physiopathology; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001931:Brain Mapping; D003287:Contrast Media / Q000008:administration & dosage; D004195:Disease Models, Animal; D006439:Hemodynamics / Q000187:drug effects*; D008297:Male; D055806:Microvessels / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D014057:Tomography, X-Ray Computed
chemical_list: D058227:Amyloidogenic Proteins; D003287:Contrast Media