title: Variation of the origin of the left common carotid artery diagnosed by CT angiography.
abstract: BACKGROUND
  The left common carotid artery (LCCA) is usually a second branch of the aortic arch that arises between the brachiocephalic trunk (BCT) and left subclavian artery; relatively frequently, it also arises from or shares a common origin with the BCT. In patients with LCCA of anomalous origin, transfemoral catheterization into the LCCA is sometimes difficult, and transbrachial or transradial approach may be recommended. We evaluated the prevalence of these variations on computed tomography (CT) angiography.
  
  
  METHODS
  We retrospectively reviewed CT angiographic images of 2,357 patients obtained using either of two 64-slice multidetector CT scanners. All patients were Japanese and underwent scanning from the aortic arch to the intracranial region; most had or were suspected of having cerebrovascular diseases.
  
  
  RESULTS
  We evaluated CT angiographic images of 2,352 patients after excluding four patients with LCCA occluded at its origin. The LCCA arose from the BCT in 141 patients (6.0 %) and had a common origin with the BCT in 130 patients (5.5 %). We found 11 aberrant right subclavian artery (0.47 %), and four of the 11 patients (36 %) had LCCA of common origin with the right common carotid artery, forming a bicarotid trunk (prevalence: 0.17 %).
  
  
  CONCLUSIONS
  The total prevalence of variations of LCCA origin diagnosed by CT angiography was 11.7 %.
authors.affiliation: Department of Diagnostic Radiology, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka, Saitama, 350-1298, Japan. auchino@saitama-med.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Uchino
authors.forename: Naoko
authors.initials: N
authors.lastname: Saito
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Okada
authors.forename: Eito
authors.initials: E
authors.lastname: Kozawa
authors.forename: Naoko
authors.initials: N
authors.lastname: Nishi
authors.forename: Waka
authors.initials: W
authors.lastname: Mizukoshi
authors.forename: Reiko
authors.initials: R
authors.lastname: Nakajima
authors.forename: Masahiro
authors.initials: M
authors.lastname: Takahashi
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D063405:Anatomic Variation; D000792:Angiography; D017536:Carotid Artery, Common / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult