title: Bovine aortic arch: a novel association with thoracic aortic dilation.
abstract: OBJECTIVE
  To investigate whether there is a link between bovine arch and thoracic aortic aneurysm.
  
  
  METHODS
  Computed tomography (CT) and magnetic resonance imaging (MRI) images of the thorax of 191 patients with dilated thoracic aortas and 391 consecutive, unselected patients as controls were retrospectively reviewed. Bovine arch was considered present if either a shared origin of the left common carotid and innominate arteries or an origin of the left common carotid from the innominate artery was identified. A chi-square test was used to evaluate the significance of differences between subgroups.
  
  
  RESULTS
  A trend towards increased prevalence of bovine arch was seen in patients with dilated aortas (26.2%) compared to controls (20.5%, p=0.12). The association was statistically significant in patients over 70 years old (31.9%, p=0.019) and when dilation involved the aortic arch (47.6%, p=0.003).
  
  
  CONCLUSIONS
  An association between bovine arch and aortic dilation is seen in older patients, and when dilation involves the aortic arch. Bovine arch should be considered a potential risk factor for thoracic aortic aneurysm.
authors: Department of Radiology, University of California, San Francisco, CA 94143-0628, USA. michael.hope@ucsf.edu
authors: C D
authors: CD
authors: Malone
authors: T H
authors: TH
authors: Urbania
authors: S E S
authors: SE
authors: Crook
authors: M D
authors: MD
authors: Hope
mesh_terms: D000328:Adult; D000368:Aged; D001013:Aorta, Thoracic / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D017545:Aortic Aneurysm, Thoracic / Q000000981:diagnostic imaging* / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed