Which statement about Doppler evaluation is true?

• A. Doppler only assesses velocity
• B. Doppler provides direct measurement of flow volume
• C. Doppler evaluates presence, velocity, character, and direction
• D. Doppler cannot assess flow direction

Answer: (C)

Doppler ultrasound reveals movement of blood by detecting frequency shifts, which tells you more than just speed. It shows whether flow is present, how fast the blood is moving, the direction of flow relative to the probe, and the flow pattern or character (such as laminar versus turbulent) seen in the waveform and color Doppler display. This combination is why the true statement is that Doppler evaluates presence, velocity, character, and direction.

Notes on the other ideas: Doppler does more than velocity, so saying it measures only speed is incomplete. It does not give a direct measurement of flow volume; to estimate volumetric flow you’d need to multiply velocity by the cross-sectional area, which requires additional measurements beyond Doppler alone. And Doppler certainly can assess flow direction, as color and spectral Doppler indicate whether flow is toward or away from the transducer.