[Principles of hemodynamics and sonographic techniques for the evaluation of arteries].

Arterosclerosis is the main cause of arterial lesions and leads to arterial stenoses. In order to preserve distal perfusion, flow velocities increase at the site of stenosis due to reduced peripheral resistance. Doppler sonography (US) allows detection of hemodynamic abnormalities at the site of stenosis and evaluation of its impact on distal flow. Several parameters and imaging features including resistive indices and systolic velocities are measured in order to characterize the degree of stenosis and its impact on perfusion. In addition, B-mode US allows morphologic evaluation of lesions. Doppler US is useful to evaluate lower limb arteries, renal arteries and neck arteries.