Doppler ultrasonography

Doppler ultrasonography is <a href="/facts/Medical_ultrasonography/Ju5BFuuV">medical ultrasonography</a> that employs the <a href="/facts/Doppler_effect/bzrK1BKf">Doppler effect</a> to perform <a href="/facts/Medical_imaging/pL6JyJEp">imaging</a> of the movement of <a href="/facts/Tissue_(biology)/H7CpML7A">tissues</a> and <a href="/facts/Body_fluid/RkAXIBVN">body fluids</a> (usually blood), and their relative velocity to the <a href="/facts/Ultrasound_probe/6Ala5r9z">probe</a>. By calculating the frequency shift of a particular sample volume, for example, flow in an artery or a jet of blood flow over a heart valve, its speed and direction can be determined and visualized.
Duplex ultrasonography sometimes refers to Doppler ultrasonography or spectral Doppler ultrasonography. Doppler ultrasonography consists of two components: brightness mode (B-mode) showing anatomy of the organs, and Doppler mode (showing blood flow) superimposed on the B-mode. Meanwhile, spectral Doppler ultrasonography consists of three components: B-mode, Doppler mode, and spectral waveform displayed at the lower half of the image. Therefore, "duplex ultrasonography" is a misnomer for spectral Doppler ultrasonography, and more exact name should be "triplex ultrasonography".
This is particularly useful in cardiovascular studies (sonography of the vascular system and heart) and essential in many areas such as determining reverse blood flow in the liver vasculature in <a href="/facts/Portal_hypertension/REmqnpER">portal hypertension</a>.

Doppler ultrasonography open-in-new

Doppler ultrasonography