title: Diagnostic performance of duplex ultrasonography in the detection of high grade internal carotid artery stenosis.
abstract: OBJECTIVE
  to establish on a national basis whether the diagnostic accuracy of carotid duplex justifies carotid surgery without preoperative angiography.
  
  
  METHODS
  prospective national multicentre study with 10 participating university and county hospitals.
  
  
  METHODS
  one hundred and thirty-four patients, aged 69+/-9 years, were subjected to routine carotid duplex ultrasonography and angiography. The influence of relevant factors on the relation between ultrasonographic and angiographic variables was evaluated using multiple regression analysis. The capacity of carotid ultrasonography to detect internal carotid artery (ICA) stenosis > or =80% was assessed by receiver operating characteristic analysis.
  
  
  RESULTS
  the correlation between peak systolic velocity in ICA (PSV(ICA)) and the angiographic degree of stenosis was strong and significantly influenced only by the applied Doppler angle. Accordingly, the optimal PSV(ICA) cutpoint values for the diagnosis of ICA stenosis > or =80% (ECST method) differed substantially (2.1 and 3.2 m/s) between the two considered angle ranges (0-49 degrees and 50-62 degrees ), the ability to identify high grade ICA stenosis being significantly better at small Doppler angles (0-49 degrees ).
  
  
  CONCLUSIONS
  ultrasonographic duplex technique identifies high grade ICA stenosis with a high degree of accuracy, which can be further improved by the application of small Doppler angles and the use of angle range specific PSV(ICA) cut-off points.
authors.affiliation: Department of Clinical Physiology, Huddinge University Hospital, Stockholm, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Jogestrand
authors.forename: M
authors.initials: M
authors.lastname: Lindqvist
authors.forename: J
authors.initials: J
authors.lastname: Nowak
mesh_terms: D000368:Aged; D000792:Angiography; D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018616:Ultrasonography, Doppler, Duplex