Which of the following is NOT one of the four aspects Doppler evaluates?

• A. presence
• B. velocity
• C. color
• D. direction

Answer: (C)

Doppler ultrasound analyzes properties of blood flow: whether flow is present, how fast it is (velocity), which way it’s moving relative to the transducer (direction), and the character of the flow (the spectral waveform pattern, indicating laminar versus turbulent flow). Color is a visualization method that encodes velocity and direction on the image, not a separate property that Doppler directly measures. So color itself isn’t one of the Doppler assessments; it’s simply how the velocity information is displayed. The other three—presence, velocity, and direction—are the fundamental measurements Doppler provides, with the fourth often stated as the flow pattern or spectral characteristics.