[Ultrasound diagnosis in acute stroke]

Doppler- and Duplex-sonography are noninvasive methods which provide helpful insight into brain blood supply by imaging extracranial neck (extracranial Doppler/Duplex) as well the intracranial basal arteries (transcranial Doppler, transcranial color-coded Duplex). Used in combination with ultrasound contrast agents, these methods are now able to supplement and often replace conventional angiography in clinical decision making processes. In acute stroke ultrasound techniques offer bedside options to localize the underlying pathogenic process and to record the actual cerebral blood flow. In addition, the Doppler method allows both detection of cerebral microemboli and their embolic source. Although technical limitation of the Doppler/Duplex method at present impairs imaging of the distal carotid arteries and of the vertebral arteries, extracranial and intracranial Doppler has been proven to be an important clinical tool providing highly useful clinical information with excellent reliability.