Continuous Doppler

Continuous-wave Doppler (CW) uses continuous transmission and reception of ultrasound waves. This is accomplished by having two separate transducer elements: one that solely sends a signal and another one that only receives signal. As no pulses are emitted, CW Doppler does not permit us to determine where the wave is reflected.

CW is not site-specific, as we only know that the depicted velocity curve stems from a reflector somewhere along the path of the ultrasound beam, which is known as the CW Doppler line. The advantage of CW Doppler is its ability to measure high velocities, which are frequently observed in pathologies of the heart, such as aortic stenosis.

Figure 1 - Example of an image obtained using continuous-wave Doppler