[Morphologic and Doppler sonographic criteria for determining the degree of stenosis of the internal carotid artery].

There is no standard classification for quantifying the degree of internal carotid artery stenoses by means of Doppler sonography. Above all this requires a clear concept of how to define the degree of stenosis morphologically, which can be described as the local lumen narrowing or the residual lumen compared with the distal internal carotid artery. Because two different physical principles are applied, the correlation between morphologic findings and hemodynamic criteria assessed by Doppler sonography can be only rough. A classification into 5 categories is presented that is practicable also with Duplex scanning and which also takes Doppler frequency analysis into account.