title: Transcranial color-coded duplex sonography for detection of distal internal carotid artery stenosis.
abstract: OBJECTIVE
  Gradation of high-grade intracranial internal carotid artery (ICA) stenosis poses a challenge to noninvasive neurovascular imaging, which seems critical for angioplasty in the ICA segments C1 and C5. We investigated cutoff values of intracranial ICA stenosis for transcranial color-coded sonography (TCCS) and compared this method with the "gold standard," digital subtraction angiography (DSA).
  
  
  METHODS
  Forty patients (mean age, 58.9 +/- 13.8 years) with intracranial ICA lesions were prospectively examined by using TCCS and DSA. Two standard TCCS coronal imaging planes were used to evaluate the intracranial ICA. In addition, a control group of 128 volunteers without cerebrovascular disease (mean age, 48.8 +/- 15.9 years) was investigated to establish standard velocity values.
  
  
  RESULTS
  DSA confirmed 96 stenoses and 8 occlusions of the intracranial ICA in the study population. In 9% and 7% of cases, stenosis confined to the C1 or C5 segment was >50% and 70%, respectively. Receiver-operating curves demonstrated cutoff values for >70% stenosis in C1 when the peak systolic velocity (PSV) was >200 cm/s (specificity, 100%; sensitivity, 71%) or the C1/submandibular ICA index was >3 (specificity, 93%; sensitivity, 86%).
  
  
  CONCLUSIONS
  TCCS is a reliable adjunctive method to detect and quantify significant stenosis of the intracranial ICA. The assessment of the C1/ICA index and peak systolic velocities maximizes the diagnostic accuracy of C1 stenosis to >70% when extracranial ICA stenosis coexists. Further studies need to be performed to compare the diagnostic accuracies of MR angiography and TCCS with that of DSA.
authors.affiliation: Department of Neurology, Vilnius University Hospital, Santariskiu Klinikos, Vilnius, Lithuania.
authors.forename: J
authors.initials: J
authors.lastname: Valaikiene
authors.forename: G
authors.initials: G
authors.lastname: Schuierer
authors.forename: B
authors.initials: B
authors.lastname: Ziemus
authors.forename: J
authors.initials: J
authors.lastname: Dietrich
authors.forename: U
authors.initials: U
authors.lastname: Bogdahn
authors.forename: F
authors.initials: F
authors.lastname: Schlachetzki
mesh_terms: D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D004453:Echoencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018615:Ultrasonography, Doppler, Color / Q000379:methods*