title: Evaluation of cerebral vasoreactivity by three-dimensional time-of-flight magnetic resonance angiography.
abstract: OBJECTIVE
  Cerebral vasoreactivity is an important indicator of the reserve capacity of the cerebral circulation. To make a quantitative analysis of cerebral vasoreactivity in individual major arterial territories, we evaluated the response to acetazolamide using three-dimensional time-of-flight magnetic resonance angiography.
  
  
  METHODS
  We examined 10 healthy volunteers and 6 patients with unilateral stenosis of the middle cerebral artery by a 1.5-T superconducting magnetic resonance imaging system. After a baseline vascular image was obtained, each subject received 17 mg/kg IV of acetazolamide; a second scan was performed 20 minutes later. Using a generally available personal computer and image analysis software, we measured the areas of the individual major arteries on collapsed axial vascular images and then calculated the vasoreactivity.
  
  
  RESULTS
  The average vasoreactivity of individual major cerebral arterial territories in the healthy volunteers was as follows: anterior cerebral artery complex, 33%; right middle cerebral artery, 71%; left middle cerebral artery, 74%; right posterior cerebral artery, 68%; and left posterior cerebral artery, 68%. In the patient group, the vasoreactivity of the stenotic middle cerebral arteries was significantly smaller than that of the nonstenotic arteries (P < .05). In addition, the nonstenotic middle cerebral arteries showed significantly less vasoreactivity than the right arteries of the healthy volunteers (P < .01).
  
  
  CONCLUSIONS
  Three-dimensional time-of-flight magnetic resonance angiography can be used to quantitatively evaluate acetazolamide-induced vasoreactivity in individual major cerebral arterial territories.
authors.affiliation: Department of Medicine, Osaka Rosai Hospital, Sakai, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Mandai
authors.forename: K
authors.initials: K
authors.lastname: Sueyoshi
authors.forename: R
authors.initials: R
authors.lastname: Fukunaga
authors.forename: M
authors.initials: M
authors.lastname: Nukada
authors.forename: I
authors.initials: I
authors.lastname: Tsukaguchi
authors.forename: M
authors.initials: M
authors.lastname: Matsumoto
authors.forename: T
authors.initials: T
authors.lastname: Kamada
mesh_terms: D000086:Acetazolamide / Q000494:pharmacology / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging*; D002545:Brain Ischemia / Q000000981:diagnostic imaging*; D002533:Cerebral Angiography; D002539:Cerebral Arterial Diseases / Q000000981:diagnostic imaging*; D002536:Cerebral Arteries / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology; D012016:Reference Values
chemical_list: D000086:Acetazolamide