title: A combined TCD and MRA screening for significant siphon portion of internal carotid artery (S-ICA) stenosis.
abstract: BACKGROUND
  We investigated whether combined transcranial Doppler (TCD) and magnetic resonance angiography (MRA) can diagnose significant stenosis (s-stenosis) of the siphon portion of the internal carotid artery (S-ICA) on digital subtraction angiography (DSA).
  
  
  METHODS
  TCD criteria cut-off peak systolic blood-flow velocity of 75 cm/s or mean blood-flow velocity of 50 cm/s, with both values more than 30% higher than in the contralateral S-ICA. MRA criterion was defined as a ≥50% signal reduction of the column width. Combined TCD and MRA criteria were fulfillment of both TCD and MRA criteria.
  
  
  RESULTS
  Among 295 vessels, seven (2%) had s-stenosis on DSA. Using TCD criteria, 16 vessels (5%) were identified to have s-stenosis, of which six (38%) had s-stenosis on DSA (sensitivity, specificity, positive predictive value [PPV], and negative predictive value [NPV] were .86, .97, .38, and .99). Using MRA criteria, 17 (6%) vessels were s-stenosis, of which seven (41%) had s-stenosis on DSA. Sensitivity, specificity, and NPV were 1.00, .97, and 1.00; however, PPV was low (.41). Combined TCD and MRA criteria identified six (2%) vessels as having s-stenosis, all were s-stenosis on DSA (PPV was 1.00).
  
  
  CONCLUSIONS
  Combined TCD and MRA examinations have similar diagnostic power to DSA.
authors.affiliation: Department of Stroke Medicine, Kawasaki Medical School, Kurashiki, Japan. aojyun@med.kawasaki-m.ac.jp
authors.forename: Junya
authors.initials: J
authors.lastname: Aoki
authors.forename: Kazumi
authors.initials: K
authors.lastname: Kimura
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Iguchi
authors.forename: Kensaku
authors.initials: K
authors.lastname: Shibazaki
authors.forename: Kazuto
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Sakai
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sakamoto
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D001783:Blood Flow Velocity; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D017585:Ultrasonography, Doppler, Transcranial