GRADING OF STENOSES IN PERIPHERAL ARTERIE S - HEMODYNAMIC AND SONOGRAPHIC PRINCIPLES

With colour duplex sonography, the identification and quantification o f arterial stenoses in peripheral arteries had become feasible in reas onable time. However, the haemodynamic considerations are more complic ated in peripheral arteries than in carotid arteries. This is attribut able to the much longer vessel length, the influences of peripheral re sistance, the frequency of multiple stenoses and combinations of occlu sion and stenosis with multiple collateral vessels. Different qualitat ive and quantitative approaches are used: b-mode sonography, spectral analysis, velocity measurements, continuity equation and estimation of systolic pressure gradients (Bernoulli equation). Although standardiz ed criteria in the grading of stenoses are not commonly used, the peak velocity ratio (PVR as a ratio of intra- and prestenotic velocity) se ems to be mathematically founded, usefully versatile and reliable.