title: Common carotid artery agenesis: duplex ultrasonographic findings.
abstract: BACKGROUND
  Agenesis of the common carotid artery (CCA) resulting in separation of the origin of the external carotid artery (ECA) and internal carotid artery (ICA) from the aortic arch is rare. Fewer than 25 cases have been reported, and correlative ultrasound data were available for only 1 of them.
  
  
  METHODS
  A 52-year-old woman visited the hospital with a 3-day history of vertigo and headache. Color-coded duplex ultrasonography performed to evaluate the carotid and vertebral arteries revealed a normal configuration on the left side. However, the right CCA could not be found; instead, there were two vessels of approximately equal size in close proximity to each other. The cerebral angiographic findings were consistent with the ultrasonographic findings. The ECA and ICA originated directly from the brachiocephalic trunk, and the ECA arose proximal to the ICA.
  
  
  CONCLUSIONS
  The ultrasonographic findings revealed absence of the CCA, the ECA and ICA originating separately from the aortic arch. Color-coded duplex ultrasonography appears to be an effective and sensitive method for detecting absence of the CCA. These findings should help to further our understanding of the embryologic development of the carotid arteries.
authors.affiliation: Department of Neurology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea.
authors.forename: Seong Jin
authors.initials: SJ
authors.lastname: Yim
authors.forename: Jung Ho
authors.initials: JH
authors.lastname: Ryu
authors.forename: Jong Sam
authors.initials: JS
authors.lastname: Baik
authors.forename: Jeong Yeon
authors.initials: JY
authors.lastname: Kim
authors.forename: Jae Hyeon
authors.initials: JH
authors.lastname: Park
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Han