title: Spatiotemporal uptake characteristics of [18]F-2-fluoro-2-deoxy-D-glucose in a rat middle cerebral artery occlusion model.
abstract: OBJECTIVE
  Alterations of cerebral glucose metabolism are well anticipated during cerebral ischemia. However, detailed spatiotemporal characteristics of disturbed cerebral glucose metabolism during acute ischemia remain largely elusive. This study aims to delineate spatiotemporal distributions of [18]F-2-fluoro-2-deoxy-D-glucose (FDG) uptake using positron emission tomography imaging, particularly at the peri-ischemic zone, and its correlation with tissue outcome.
  
  
  METHODS
  The intraluminal suture middle cerebral artery occlusion model was used to induce focal cerebral ischemia in rats (n=48). All animals underwent sequential MRI and FDG positron emission tomography imaging at different times (30-150 minutes) after middle cerebral artery occlusion. MR and positron emission tomography images were coregistered. FDG uptake in the peri-ischemic zone was assessed in relation to middle cerebral artery occlusion duration, cerebral blood flow, apparent diffusion coefficient, and 24-hour T2 lesions.
  
  
  RESULTS
  Elevated FDG uptake was consistently observed at the peri-ischemic zone surrounding the presumed ischemic core with low FDG uptake. Both the spatial volume and the uptake level of the hyper-uptake region were inversely correlated with the duration of middle cerebral artery occlusion. The hyper-uptake regions exhibited a mild reduction of cerebral blood flow (28.2±3.2%) and apparent diffusion coefficient (9.1±1.4%) when compared with that in the contralateral hemisphere. Colocalization analysis revealed that, with reperfusion, an average of 12.1±1.7% of the hyper-uptake volume was recruited into final infarction.
  
  
  CONCLUSIONS
  Elevated FDG uptake at the peri-ischemic zone is consistently observed during acute cerebral ischemia. The region with elevated FDG uptake likely reflects viable tissues that can be salvaged with reperfusion. Therefore, acute FDG positron emission tomography imaging might hold promise in the management of patients with acute stroke.
authors.affiliation: Department of Radiology, University of North Carolina at Chapel Hill, NC, USA.
authors.forename: Hong
authors.initials: H
authors.lastname: Yuan
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Frank
authors.forename: Yonglong
authors.initials: Y
authors.lastname: Hong
authors.forename: Hongyu
authors.initials: H
authors.lastname: An
authors.forename: Cihat
authors.initials: C
authors.lastname: Eldeniz
authors.forename: Jingxin
authors.initials: J
authors.lastname: Nie
authors.forename: Adomas
authors.initials: A
authors.lastname: Bunevicius
authors.forename: Dinggang
authors.initials: D
authors.lastname: Shen
authors.forename: Weili
authors.initials: W
authors.lastname: Lin
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D002343:Carotid Artery, Internal / Q000601:surgery; D002560:Cerebrovascular Circulation / Q000502:physiology; D004195:Disease Models, Animal; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D049268:Positron-Emission Tomography / Q000295:instrumentation / Q000379:methods*; D051381:Rats; D020318:Rats, Long-Evans; D015424:Reperfusion / Q000379:methods; D013997:Time Factors
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: FDG PET; acute ischemic stroke; cerebral glucose metabolism