[Importance of duplex ultrasound in diagnosis of venous diseases].

The development of blood flow measurement by Doppler frequency shift has been a very significant advance in phlebological diagnosis. The difficulty with ultrasonographic Doppler diagnosis lies in the potential homogeneity of the sounds even when the blood flow varies in nature. Therefore, anatomic variation in blood vessels may lead to misinterpretation. As a new noninvasive method, Duplex ultrasonography reflects substantial progress in the diagnosis of venous diseases. This method combines Doppler ultrasonography and real-time sonography, allowing precise interpretation of the sounds in relation to the vessel being examined.