What is Doppler Ultrasonography?
Doppler US allows the imaging and quantification of blood flow velocity in vessels. It is based on the Doppler effect, which refers to the change in sound wave frequency and wavelength that occurs whenever the source of reflected waves (e.g., blood) is moving with respect to the detector (e.g., a transducer). Echoes from blood flowing toward a transducer will have higher frequencies and shorter wavelengths than blood flowing away from a transducer.
