The wall filter is also known as ______.

The wall filter is also known as ______.

• A. Notch filter
• B. Low pass filter
• C. Bandpass filter
• D. High pass filter

Answer: (D)

The wall filter works as a high-pass filter. In Doppler ultrasound, tissue and vessel walls can heartbeat or move, producing low-frequency Doppler shifts that clutter the signal. By attenuating these low-frequency components, a high-pass filter suppresses wall motion clutter while preserving the higher-frequency shifts from moving blood cells. That’s why the wall filter is described as a high-pass filter. Notch filters remove a narrow band, low-pass filters let through low frequencies, and bandpass filters pass a specific range, none of which match the wall-filter role as effectively.

The wall filter works as a high-pass filter. In Doppler ultrasound, tissue and vessel walls can heartbeat or move, producing low-frequency Doppler shifts that clutter the signal. By attenuating these low-frequency components, a high-pass filter suppresses wall motion clutter while preserving the higher-frequency shifts from moving blood cells. That’s why the wall filter is described as a high-pass filter. Notch filters remove a narrow band, low-pass filters let through low frequencies, and bandpass filters pass a specific range, none of which match the wall-filter role as effectively.