Diagnosis of Moyamoya Disease with Transcranial Doppler Sonography: Correlation Study with Magnetic Resonance Angiography

Background and Purpose. Although the diagnosis of moyamoya disease may be confirmed by digital subtraction angiography, recent studies have shown the accuracy of mag netic resonance angiography. Characteristics of transcranial Doppler, a noninvasive and cost‐effective method, and specific transcranial Doppler parameters reflecting distinct vascular status in moyamoya disease are explored. Method and Patients. Consecutive patients (> 15 years of age) diagnosed with moyamoya disease by a typical clinical history and digital sub traction angiography or magnetic resonance angiography were included. The statuses of the anterior, middle, and posterior cerebral arteries were graded as stage 1, stage 2, and stage 3 by magnetic resonance angiography. Mean flow velocity and pulsatility index were compared between these groups, and the receiver operating characteristic analysis was used to define transcranial Doppler criteria for distinct vascular status. Results. Forty‐five patients were included (37 women; mean age, 34.9 ± 11.4 years). Mean flow velocity was higher and pulsatility index was lower in stage 2 ( P < .01), while mean flow velocity was lower and pulsatility index was higher in stage 3 than in stage 1 ( P < .01). Cutoff values reflecting stenosis or occlusion with substantial sensitivity and specificity were as follows: mean flow velocity > 85 cm/s or pulsatility index < 0.60 for stage 2, and mean flow velocity < 50 cm/s for stage 3 of middle cerebral artery; mean flow velocity > 80 cm/s or pulsatility index < 0.60 for stage 2 of anterior cerebral artery; and mean flow velocity > 60 cm/s or pulsatility index < 0.60 for stage 2 of posterior cerebral artery. Conclusion. Transcranial Doppler may help to refine magnetic resonance angiography findings and thus help clinicians differentiate severity or stages of moyamoya disease.