Pilot Study of New Diagnostic Criteria for Middle Cerebral Artery Stenosis by Transcranial Doppler

Abstract

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. 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). 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. 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.