title: Geometric classification of the carotid siphon: association between geometry and stenoses.
abstract: OBJECTIVE
  The development of intracranial internal carotid artery (ICA) stenoses may be associated with the morphology of the siphon. The aim is to quantitatively characterize the geometry of ICA, and develop a classifier of the ICA shape in relation to the location and incidence of stenoses.
  
  
  METHODS
  The ICA geometry from 74 subjects was analyzed by means of image-based computational techniques. The siphon was split into two bends, and was described in terms of curvature radius, radius of vessel, angle of bending, and length. Differences of geometry between ICA classes were assessed in control group, consisted of 30 subjects without stenoses. In stenosed group, the association between the ICA classes and the incidence of stenoses were investigated and validated by hemodynamic simulation.
  
  
  RESULTS
  The curvature radius and angle of the posterior bend were significantly different between ICA classes, as well as the angle between the two bends. An innovative classifier was developed with the three geometric parameters. The ICA classification was found associated with the incidence of stenoses at the siphon.
  
  
  CONCLUSIONS
  Geometric factors relative to the ICA were correlated with the location and incidence of stenoses at the siphon. The present work has potential implications in the quest for hemodynamic factors contributing to the initiation and progression of intracranial ICA stenoses.
authors.affiliation: Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing, 100191, PR China.
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.forename: Fang
authors.initials: F
authors.lastname: Pu
authors.forename: Shuyu
authors.initials: S
authors.lastname: Li
authors.forename: Sheng
authors.initials: S
authors.lastname: Xie
authors.forename: Yubo
authors.initials: Y
authors.lastname: Fan
authors.forename: Deyu
authors.initials: D
authors.lastname: Li
mesh_terms: D000368:Aged; D002343:Carotid Artery, Internal / Q000033:anatomy & histology* / Q000502:physiology; D016893:Carotid Stenosis / Q000209:etiology*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular