title: Variations in the circle of Willis in the New Zealand white rabbit.
abstract: OBJECTIVE
  The New Zealand White rabbit (NZWR) serves an important role as an experimental model for vascular research, specifically in the area of stroke. Here the authors document vascular variations in the circle of Willis (COW).
  
  
  METHODS
  Subselective internal carotid digital subtraction angiography was performed in 100 NZWRs.
  
  
  RESULTS
  Important variations include hypoplasia in 36%, duplication of the middle cerebral artery in 29%, asymmetries of the posterior region in 19%, and multiple variations in 28%. The complete classical symmetric COW without significant variation is present in fewer than 30% of animals.
  
  
  CONCLUSIONS
  With recognition of the variations, the NZWR becomes an improved research model.
authors.affiliation: College of Medicine at the University of Arkansas for Medical Sciences, 4301 W Markham St, Slot 556, Little Rock, AR 72205-7199, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Caldwell
authors.forename: Rene
authors.initials: R
authors.lastname: Flores
authors.forename: John
authors.initials: J
authors.lastname: Lowery
authors.forename: Aliza T
authors.initials: AT
authors.lastname: Brown
authors.forename: William C
authors.initials: WC
authors.lastname: Culp
mesh_terms: D015901:Angiography, Digital Subtraction / Q000379:methods*; D000818:Animals; D002941:Circle of Willis / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D023421:Models, Animal; D011817:Rabbits