title: Screen for intracranial dural arteriovenous fistulae with carotid duplex sonography.
abstract: OBJECTIVE
  Early diagnosis and management of intracranial dural arteriovenous fistulae (DAVF) may prevent the occurrence of stroke. This study aimed to identify the best carotid duplex sonography (CDS) parameters for screening DAVF.
  
  
  METHODS
  63 DAVF patients and 170 non-DAVF patients received both CDS and conventional angiography. The use of seven CDS haemodynamic parameter sets related to the resistance index (RI) of the external carotid artery (ECA) for the diagnosis of DAVF was validated and the applicability of the best CDS parameter set in 20 400 patients was tested.
  
  
  RESULTS
  The CDS parameter set (ECA RI (cut-off point = 0.7) and internal carotid artery (ICA) to ECA RI ratio (cut-off point = 0.9)) had the highest specificity (99%) for diagnosis of DAVF with moderate sensitivity (51%). Location of the DAVF was a significant determinant of sensitivity of detection, which was 70% for non-cavernous DAVF and 0% for cavernous sinus DAVF (p<0.001). The above parameter set detected abnormality in 92 of 20 400 patients. These abnormalities included DAVF (n = 25), carotid stenosis (n = 32), vertebral artery stenosis (n = 7), intracranial arterial stenosis (n = 6), head and neck tumour (n = 3) and unknown aetiology (n = 19).
  
  
  CONCLUSIONS
  Combined CDS parameters of ECA RI and ICA to ECA RI ratio can be used as a screening tool for the diagnosis of DAVF.
authors.affiliation: Department of Neurology and Stroke Centre, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: L-K
authors.initials: LK
authors.lastname: Tsai
authors.forename: S-J
authors.initials: SJ
authors.lastname: Yeh
authors.forename: Y-C
authors.initials: YC
authors.lastname: Chen
authors.forename: H-M
authors.initials: HM
authors.lastname: Liu
authors.forename: J-S
authors.initials: JS
authors.lastname: Jeng