Color Doppler displays which values, not which values?

Color Doppler displays which values, not which values?

• A. Peak values, not average values
• B. Average values, not peak values
• C. Both peak and average values
• D. None

Answer: (B)

Color Doppler represents the average velocity of blood within the sample volume, not the instantaneous peak velocity of individual cells. The system estimates velocity by averaging Doppler shifts over a short time window (ensemble) for each pixel and then displays that mean velocity with color (direction indicated by hue). This makes the image robust to momentary speed spikes and noise and focuses on overall flow direction and speed rather than the highest speed that might occur moment-to-moment. If you need peak velocities, you’d use spectral Doppler waveform instead.

Color Doppler represents the average velocity of blood within the sample volume, not the instantaneous peak velocity of individual cells. The system estimates velocity by averaging Doppler shifts over a short time window (ensemble) for each pixel and then displays that mean velocity with color (direction indicated by hue). This makes the image robust to momentary speed spikes and noise and focuses on overall flow direction and speed rather than the highest speed that might occur moment-to-moment. If you need peak velocities, you’d use spectral Doppler waveform instead.