title: The role of the occipital artery in the diagnosis of intracranial dural arteriovenous fistula using duplex sonography.
abstract: OBJECTIVE
  The occipital artery is usually a main feeding artery of an intracranial dural arteriovenous fistula. The aim of this study was to establish the role of the OA in the diagnosis of DAVFs by using duplex sonography.
  
  
  METHODS
  We first compared the clinical features between patients with DAVFs having and not having the OA as one of feeding arteries in 181 consecutive patients with DAVFs. Second, we investigated the OA by using duplex sonography in 60 control subjects to test the accessibility. Finally, we studied 24 DAVF and 60 non-DAVF patients to validate the diagnostic performances of duplex sonography. Hemodynamic parameters, including the resistance index and flow velocity, were analyzed.
  
  
  RESULTS
  Half of the DAVFs (51%) had the OA as one of feeding arteries. DAVFs with the OA as one of the feeders were more likely located at noncavernous sinuses; to belong to types IIb, IIa+b, III, IV, or V; and to be associated with aggressive manifestations compared with DAVFs without the OA as a feeder (P < .05). Accessibility of the OA by using duplex sonography was 100%. The resistance index was lower and flow velocity was higher in the OA among patients with DAVFs compared with control subjects (P < .001). An OA resistance index <0.76 yielded a sensitivity and specificity of 96% and 97%, respectively, for the diagnosis of a DAVF.
  
  
  CONCLUSIONS
  The OA resistance index can be used to screen for DAVFs having the OA as one of feeding arteries, and this kind of DAVF was usually associated with nonbenign clinical courses.
authors.affiliation: Department of Neurology and Stroke Centre, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: B-L
authors.initials: BL
authors.lastname: Tee
authors.forename: L-K
authors.initials: LK
authors.lastname: Tsai
authors.forename: C-C
authors.initials: CC
authors.lastname: Lai
authors.forename: S-C
authors.initials: SC
authors.lastname: Tang
authors.forename: Y-A
authors.initials: YA
authors.lastname: Chen
authors.forename: C-L
authors.initials: CL
authors.lastname: Chen
authors.forename: J-S
authors.initials: JS
authors.lastname: Jeng
mesh_terms: D000368:Aged; D020785:Central Nervous System Vascular Malformations / Q000000981:diagnostic imaging*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging*; D004453:Echoencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018616:Ultrasonography, Doppler, Duplex / Q000379:methods*