Transcranial color-coded duplex sonography.

Transcranial color-coded duplex sonography (TCCS) enables the reliable assessment of intracranial stenoses, occlusions, and cross-flow through the circle of Willis without using potentially hazardous compression tests. Transpulmonary ultrasound contrast agents (UCAs) increase the number of conclusive TCCS investigations, which suggests that UCAs may provide the conclusive evaluation of intracranial arteries in most patients with ischemic cerebrovascular disease. Further, contrast-enhanced TCCS may become an important tool both for the management of acute ischemic stroke by assessing intracranial hemodynamics and the displacement and diameter changes in supratentorial ventricles. TCCS is useful for the detection and monitoring of intracranial vasospasm, may visualize larger supratentorial hematomas with subcortical location and hemorrhagic transformation of ischemic infarcts, and provides the incidental detection of cerebral aneurysms and arteriovenous malformations. Second-generation UCAs and new ultrasound machines are very likely to further increase the frequency of conclusive TCCS studies. Power-based three-dimensional, contrast-enhanced TCCS is an important further development, which would make the method much less operator dependent. Site-targeted UCAs appear to provide a new and exciting method for ultrasonic diagnosis and management of patients with ischemic cerebrovascular disease.