[Basic characteristics of duplex sonography in the assessment of lower limb arterial circulation]

Dulpex and color duplex ultrasonography of lower limb arteries are valuable non-invasive diagnostic methods in the pathology of vascular diseases and a major step in diagnostics and in follow-up of hemodynamic and morphologic characteristics.

The method consists of image analysis and analysis of Doppler information. Real-time-B mode is used to visualize the anatomy of blood vessels and other pathological lesions. Doppler information based on the Doppler effect determine the pulse wave i.e. the shape of flow velocity--hemodynamic characteristics. Spectral analysis is the most important element of Doppler examination of the lower limb peripheral arteries. Based on the spectral analysis, there are four stages of lower limb arterial disease: normal findings--1% - 19% diameter reduction; medium stenosis--artery diameter reduction of 20% - 49%; high level stenosis--artery diameter reduction of 50% - 100%; occlusion--no flow detected within the imaged arterial segment. In the first place, both iliac arteries are examined, which is followed with femoral, popliteal and crural arteries. The examination of iliac arteries is carried out with a 3.5 MHz transducer, and other peripheral arteries of the lower limbs are examined with a 7, 5 or 5 MHz transducer.

Color Doppler is an extremely valuable diagnostic method in detecting pathology of the lower limb arteries. With high reliability level arterial insufficiency and pathological arterial segments are diagnosed by a duplex-Doppler.