Which Doppler control most directly reduces the display of low-velocity Doppler signals when increased?

Which Doppler control most directly reduces the display of low-velocity Doppler signals when increased?

• A. Packet size
• B. Wall filter
• C. Gain
• D. Dynamic range

Answer: (B)

The wall filter directly targets low-frequency Doppler components. Tissue motion and clutter produce slow, low-velocity Doppler shifts near baseline. Increasing the wall filter raises the cutoff frequency so those slow signals are suppressed, which reduces the display of low-velocity Doppler signals and helps reveal the true blood flow signals that are higher in velocity. Other controls don’t specifically suppress these slow components: packet size affects data handling, gain boosts all signals, and dynamic range changes how wide a range of amplitudes is shown.

The wall filter directly targets low-frequency Doppler components. Tissue motion and clutter produce slow, low-velocity Doppler shifts near baseline. Increasing the wall filter raises the cutoff frequency so those slow signals are suppressed, which reduces the display of low-velocity Doppler signals and helps reveal the true blood flow signals that are higher in velocity.

Other controls don’t specifically suppress these slow components: packet size affects data handling, gain boosts all signals, and dynamic range changes how wide a range of amplitudes is shown.