What specific measurement is tested by a Doppler flow phantom that is not directly tested by simple structural imaging?

• A. Frame rate
• B. Color Doppler brightness
• C. Spectral Doppler velocity accuracy
• D. Transducer temperature

Answer: (C)

Doppler velocity measurements are the focus here. A Doppler flow phantom provides a controlled, known flow within a vessel-mimicking channel so the system’s spectral Doppler can be calibrated against real velocities. This lets you verify how accurately the device measures velocity values (including peak and mean velocities and the waveform), as well as how well angle correction and Doppler scaling are working. Simple structural imaging, by contrast, uses B-mode to show anatomy and does not produce or quantify flow velocity, so it can’t assess spectral Doppler velocity accuracy.