Transcranial power-mode duplex ultrasound in two patients with moyamoya syndrome.

Moyamoya syndrome is characterized by the reticulated collateralization of the intracranial vasculature distal to an occlusion of proximal intracranial vessels. In the present study this pathology was visualized in 2 patients, aged 29 and 32 years, using transcranial color Doppler imaging (TCDI). Digital subtraction angiography in both patients revealed stenosis of the intracranial portion of the internal carotid arteries, occlusion and stenosis of several cerebral arteries, and a bilateral reticulated collateral network particularly in the region of both basal ganglia, typical of moyamoya syndrome. TCDI with power-mode Doppler depicted parts of the intracranial collateral network, not possible using conventional color-flow Doppler. TCDI with power-mode Doppler permitted better visualization of intracranial vascular pathology in comparison to conventional color-flow Doppler, enabling a rapid and noninvasive diagnosis of rare cerebrovascular anomalies.