Continuous wave Doppler is another technique used to assess high-velocity flow, such as in the evaluation of valvular stenosis or regurgitation. It uses two separate transducer crystals, one for transmitting ultrasound waves and the other for receiving the reflected waves. Continuous wave Doppler Ultrasoundallows for the assessment of flow velocities along the entire Doppler beam, but it does not provide precise location information. Care should be taken to avoid the "aliasing" artifact, which occurs when the velocity exceeds the Nyquist limit, resulting in a wrap-around of the spectral waveform. Adjusting the scale or using a higher-frequency transducer can help overcome this limitation.
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