title: Carotid ultrasound criteria for detecting intracranial carotid stenosis.
abstract: OBJECTIVE
  This study attempted to establish carotid ultrasound criteria for identifying stenosis of the intracranial internal carotid artery (ICA) and middle cerebral artery (MCA).
  
  
  METHODS
  Two hundred and fifty-five patients were enrolled. Ultrasound measurements for common carotid artery (CCA) and ICA were as follows: flow volume (FV), peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility index (PI) and resistance index (RI). The sensitivity and specificity of the ultrasound criteria for determining intracranial ICA or MCA>or=50% stenosis were calculated.
  
  
  RESULTS
  The criteria identified for detecting intracranial ICA>or=50% stenosis were ICA FV<159 ml/min, ICA PSV<33 cm/s and CCA PSV<42 cm/s. When ICA PSV<33 cm/s was combined with CCA PSV<42 cm/s, sensitivity increased to 82%, with 91% specificity. The criteria identified for detecting MCA>or=50% stenosis were CCA FV<285 ml/min, ICA FV<179 ml/min, ICA PSV<33 cm/s, >35% reduction in FV in the CCA, >40% reduction in FV in ICA, and >35% reduction in PSV in ICA. When these criteria were combined, sensitivity increased to 69%, with 85% specificity.
  
  
  CONCLUSIONS
  This study demonstrated that ultrasound criteria are sensitive and specific for detecting intracranial ICA and MCA significant obstruction.
authors.affiliation: Department of Neurology, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Chiayi, Taiwan.
authors.forename: Jiann-Der
authors.initials: JD
authors.lastname: Lee
authors.forename: Shan-Jin
authors.initials: SJ
authors.lastname: Ryu
authors.forename: Yeu-Jhy
authors.initials: YJ
authors.lastname: Chang
authors.forename: Kai-Cheng
authors.initials: KC
authors.lastname: Hsu
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Chen
authors.forename: Ying-Chih
authors.initials: YC
authors.lastname: Huang
authors.forename: Meng
authors.initials: M
authors.lastname: Lee
authors.forename: Ming-Chang
authors.initials: MC
authors.lastname: Hsiao
authors.forename: Tsong-Hai
authors.initials: TH
authors.lastname: Lee
mesh_terms: D000792:Angiography / Q000379:methods; D001783:Blood Flow Velocity; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D006801:Humans; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018616:Ultrasonography, Doppler, Duplex / Q000379:methods* / Q000592:standards*