E. Bartels
Center for Neurological Vascular Diagnostics – Munich, Germany

In this lecture the typical ultrasonographic findings in cerebral occlusive disease will be presented.
Data concerning the sensitivity and specificity of TCCS in intracranial stenosis remain limited. Furthermore, limited criteria for the quantification of intracranial stenosis by TCCS are available. The classification is based on conventional TCD studies.
The degree of stenosis is estimated on the basis of the changes of the Doppler spectrum (increased flow velocities in the site of the stenosis, and flow disturbancies upstream and downstream from the lesion). TCCS provides information on the localization of the stenosis. Using the frequency dependent color-coding, the site of the stenosis can be more easily recognized due to the aliasing phenomenon.