ARDMS RDMS AB-Abdomen Question # 38 Topic 4 Discussion

When the sample volume (gate) is too large, it captures signals from both the vessel and surrounding tissues or adjacent flows. This leads to a broadening of the spectral waveform and produces "spectral noise" or "spectral broadening," reducing the accuracy of velocity measurements and waveform analysis. Aliasing results from high velocity relative to the Nyquist limit, not from gate size.

According to Zwiebel’s Introduction to Vascular Ultrasound:

“Increasing the sample volume beyond the vessel size causes spectral broadening, resulting in spectral noise and inaccurate Doppler measurements.”