Pulse-Doppler ultrasound and its clinical application.

Doppler devices can provide clinically useful information about blood flow. This paper describes how a pulse-Doppler instrument has been linked to a B-scan machine so that flow patterns in any ultrasonically accessible vessel can be monitored from the skin surface. The same transducer is used for both modes of investigation to enable accurate and reliable positioning of the sample-volume. After briefly summarizing the principles of continuous-wave and pulse-Doppler operation, the concepts and relative advantages of coherent and non-coherent detection are explained. The potential clinical uses of the pulse-echo-Doppler hybrid and Doppler devices in general are then discussed.