[Reliability and limitations of Doppler sonography of the cranial arteries ].

High-grade stenoses and occlusions of the internal carotid artery can be detected and differentiated with high accuracy by Doppler sonography. The hemodynamic effect of obliterations of the subclavian and innominate artery on cerebral blood flow readily can be examined too. With lower-grade stenoses of the supraaortic arteries, there are some limitations in accuracy which are discussed in detail. In some cases, Doppler sonography can replace angiography, but it still must be considered, that this method depends greatly on experience.