Abstract
With the help of colour-coded duplex sonography intracranial vessels can be displayed within the gray scale image. The sample volume of the pulsed Doppler device can be placed optimally within intracranial vessels. Angle correction is possible and allows the quantification of flow velocities. Indications for colour coded Doppler sonography are diseases such as intracranial haemorrhage, hydrocephalus, meningoencephalitis, hypoxaemic-ischaemic insults, brain oedema, brain death, vasculitis and cerebrovascular malformations. Additionally all cardiovascular malformations such as a leakage of the aortic "windkessel" or obstructions of the left heart are associated with pathologic flow profiles in the intracranial arteries.