Transcranial color-coded duplex sonography (TCCS) enables the reliable assessment of intracranial stenoses (sensitivity 94-100%, specificity 99-100%), occlusions (middle cerebral artery: sensitivity 93-100%, specificity 98-100%) and cross-flow through the anterior (sensitivity 98%, specificity 100%) and posterior (sensitivity 84%, specificity 94%) communicating arteries without using potentially dangerous compression tests, as well as the midline shift in hemispheric infarcts. Ultrasound contrast agents (UCAs) increase the number of conclusive TCCS studies and allow the definite evaluation of intracranial arteries in most patients. TCCS is also useful for diagnosis and monitoring of vasospasm and detection of supratentorial hematomas (sensitivity 94%, specificity 95%) and aneurysms (sensitivity per patient 40-78%, specificity 90-91%), and may identify arteriovenous malformations. New developments are (1) UCAs that may increase the number of conclusive TCCS studies, (2) cerebral perfusion assessment, (3) measurement of arteriovenous cerebral transit time, which might enable the detection of small-vessel disease, and (4) site-targeted UCAs that may improve diagnosis and local drug delivery.
Copyright 2003 S. Karger AG, Basel