[The value of duplex sonography in cerebral ischemia]

Doppler color flow imaging (DCFI) is a new ultrasound technique for the assessment of extracranial arterial disease. This system is a further development of conventional duplex systems. The new technique provides a real-time gray-scale echotomogram (B-mode) and simultaneously superimposed color-coded Doppler signals of intravascular blood flow. The advantages of the DCFI are improved identification of vascular structures, faster data acquisition, shorter examination time, better characterization of the surface, structure and extent of plaques with easier detection of ulcerative lesions or thrombotic material. Due to these advantages, the sensitivity for the detection of lesions which may cause arterio-arterial embolisms to the brain, is increased. With DCFI, it is possible to visualize the extracranial portion of the vertebral arteries. This improves the evaluation of the vertebro-basilar circulation. DCFI is a safe and fast method in the follow-up procedure of symptomatic and asymptomatic patients and after carotid endarterectomy. Using DCFI, the interaction between morphology and hemodynamics in the extracranial vessels can be analyzed, which is important particularly for the understanding of the potential risk of different plaque types.