To minimize color Doppler aliasing, which adjustment is most effective?

To minimize color Doppler aliasing, which adjustment is most effective?

• A. Decrease color box width
• B. Increase PRF
• C. Increase depth
• D. Increase PRF

Answer: (D)

Color Doppler aliasing happens when the Doppler shift exceeds the Nyquist limit, which is half the pulse repetition frequency. Since PRF sets how often velocity samples are taken, increasing PRF raises the Nyquist limit and allows higher velocities to be measured without wrap-around. The most effective way to minimize aliasing is to increase PRF. In practice, you can raise PRF by imaging at a shallower depth or using a narrower color box to boost frame rate, but depth changes can counterintuitively reduce PRF, and narrowing the box helps only indirectly. So the direct, strongest action is increasing PRF.

Color Doppler aliasing happens when the Doppler shift exceeds the Nyquist limit, which is half the pulse repetition frequency. Since PRF sets how often velocity samples are taken, increasing PRF raises the Nyquist limit and allows higher velocities to be measured without wrap-around. The most effective way to minimize aliasing is to increase PRF. In practice, you can raise PRF by imaging at a shallower depth or using a narrower color box to boost frame rate, but depth changes can counterintuitively reduce PRF, and narrowing the box helps only indirectly. So the direct, strongest action is increasing PRF.