Comparison of transcranial power Doppler and contrast-enhanced color-coded sonography in the identification of intracranial arteries.

Power-based transcranial color-coded sonography and contrast-enhanced transcranial color-coded sonography are ultrasonographic techniques that allow improved visualization of vascular structures. The present study was designed to investigate and compare the diagnostic capacity and applicability of both methods in the assessment of intracranial vessels of the circle of Willis (33 patients) and the vertebrobasilar system (21 patients). Compared to conventional transcranial color-coded sonography, both power-based and contrast-enhanced transcranial color-coded sonography improved the diagnostic sensitivity in identifying peripheral segments and small vessels of the circle of Willis. Contrast-enhanced transcranial color-coded sonography was significantly superior to power-based transcranial color-coded ultrasonography in the depiction of the second segment of the middle cerebral artery (66 of 66 versus 60 of 66, P < 0.005), both segments of the anterior cerebral artery (66 of 66 versus 56 of 66 for the A1 segment, P < 0.005; 61 of 66 versus 44 of 66 for the A2 segment, P < 0.005), the first segment of the posterior cerebral artery (66 of 66 versus 55 of 66, P < 0.005), and the basilar artery using the transtemporal approach (21 of 21 versus 15 of 21, P < 0.05). Using the transforaminal approach contrast-enhanced transcranial color-coded real-time sonography did not increase fine resolution of the vertebrobasilar system compared to power Doppler sonography. In conclusion, contrast-enhanced transcranial color-coded real-time sonography further improves the diagnostic potential of power Doppler sonography in the identification of vascular structures of the circle of Willis. Contrast-enhanced transcranial color-coded sonography and power Doppler sonography are equally effective in visualizing the vertebrobasilar system with branches.