title: Hyperperfusion on perfusion computed tomography following revascularization for acute stroke.
abstract: OBJECTIVE
  To describe the findings of hyperperfusion on perfusion computed tomography (CT) in four patients following revascularization for acute stroke.
  
  
  METHODS
  In 2002-2003, among a series of 6 patients presenting with an acute stroke and treated with intra-arterial thrombolysis, we observed the presence of hyperperfusion in 3 patients on the follow-up CT perfusion. We included an additional patient who was treated with intravenous thrombolysis and who had hyperperfusion on the follow-up CT perfusion. We retrospectively analyzed their CT perfusion maps. Cerebral blood volume (CBV) and cerebral blood flow (CBF) maps were compared between the affected territory and the normal contralateral hemisphere.
  
  
  RESULTS
  In the four patients, the mean CBV and CBF were 3.6 +/- 2.0 ml/100 g and 39 +/- 25 ml/100 g/min in the affected territory compared to the normal side (mean CBV = 2.7 +/- 2.1 ml/100 g, mean CBF = 27 +/- 23 ml/100 g/min). There was no intracranial hemorrhage in the hyperperfused territories. At follow-up CT, some hyperperfused brain areas progressed to infarction, while others retained normal white to gray matter differentiation.
  
  
  CONCLUSIONS
  CT perfusion can demonstrate hyperperfusion, which can be seen in an ischemic brain territory following recanalization.
authors.affiliation: Department of Radiology and Department of Neurology, Ottawa Hospital, Ottawa, Canada. thnguyen@ottawahospital.on.ca
authors.forename: T B
authors.initials: TB
authors.lastname: Nguyen
authors.forename: C
authors.initials: C
authors.lastname: Lum
authors.forename: J D
authors.initials: JD
authors.lastname: Eastwood
authors.forename: P K
authors.initials: PK
authors.lastname: Stys
authors.forename: M
authors.initials: M
authors.lastname: Hogan
authors.forename: M
authors.initials: M
authors.lastname: Goyal
mesh_terms: D000368:Aged; D001810:Blood Volume / Q000502:physiology; D002533:Cerebral Angiography; D002544:Cerebral Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D015424:Reperfusion; D012189:Retrospective Studies; D020521:Stroke / Q000188:drug therapy* / Q000503:physiopathology; D015912:Thrombolytic Therapy; D014057:Tomography, X-Ray Computed / Q000379:methods*