Power Doppler color encoding uses which property to signal flow color?

Power Doppler color encoding uses which property to signal flow color?

• A. Amplitude of the Doppler signal
• B. Frequency shift of the Doppler signal
• C. Phase shift of the signal
• D. Velocity magnitude only

Answer: (A)

Power Doppler encodes flow by the strength of the Doppler signal—that is, the amplitude (or power) of the backscattered Doppler signal. This color intensity reflects how much moving blood signal is present, not how fast it’s moving. Because it relies on signal energy rather than frequency shifts, it is more sensitive to low-velocity flow and can detect flow in vessels where standard Doppler might miss it, but it does not convey the direction of flow. The other properties listed—frequency shift (which standard color Doppler uses to show velocity and direction), phase shift, or velocity magnitude alone—do not define power Doppler color signaling.

Power Doppler encodes flow by the strength of the Doppler signal—that is, the amplitude (or power) of the backscattered Doppler signal. This color intensity reflects how much moving blood signal is present, not how fast it’s moving. Because it relies on signal energy rather than frequency shifts, it is more sensitive to low-velocity flow and can detect flow in vessels where standard Doppler might miss it, but it does not convey the direction of flow. The other properties listed—frequency shift (which standard color Doppler uses to show velocity and direction), phase shift, or velocity magnitude alone—do not define power Doppler color signaling.