title: Pilot study of new diagnostic criteria for middle cerebral artery stenosis by transcranial Doppler.
abstract: OBJECTIVE
  Current criteria for middle cerebral artery (MCA) stenosis by transcranial Doppler were mainly based on the flow velocity acceleration, ignoring other useful parameters. We tested the accuracy of new criteria using magnetic resonance angiography (MRA) as the confirmative method.
  
  
  METHODS
  A compositive score for each MCA was calculated according to following parameters: Velocity Scale (score 0-6 for peak systolic velocity <140 to > or = 300 cm/second), Hemodynamic Scale (score 0-5 for diffuse or focal velocity increase; score 0-6 for differences between bilateral MCA; score 17 for damping velocity), and Spectrum Scale (score 0-2 for normal spectrum, turbulence, and musical murmurs).
  
  
  RESULTS
  The median scores in normal-mild, moderate, and severe groups on MRA differed significantly (P < .001). The optimal cutoff score for <50% and > or = 50% stenosis was 3 with the PPV of 72.3% (95% confidence interval [CI]: 65.3% to 78.5%) and negative predictive value (NPV) of 89.5% (95% CI: 85.9% to 92.3%), for moderate and severe stenosis was 6 with the PPV of 85.9% (95% CI: 76.7% to 92.0%) and NPV of 61.9% (95% CI: 50.6% to 72.1%). Both scores performed better than peak systolic or mean velocity.
  
  
  CONCLUSIONS
  This new method was feasible and reliable and showed some advantages over the velocity-only method. Further studies using digital subtraction angiography as the gold standard are needed to ameliorate the new criteria.
authors.affiliation: Department of Medicine &Therapeutics, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Hao
authors.forename: Shan
authors.initials: S
authors.lastname: Gao
authors.forename: Thomas Wai Hong
authors.initials: TW
authors.lastname: Leung
authors.forename: Ming Hui
authors.initials: MH
authors.lastname: Guo
authors.forename: Yong
authors.initials: Y
authors.lastname: You
authors.forename: Ka Sing
authors.initials: KS
authors.lastname: Wong
mesh_terms: D000465:Algorithms; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*