What technique can help prevent "ghosting" in ultrasound imaging?

Increasing the wall filter is an effective technique to help prevent "ghosting" in ultrasound imaging. Ghosting refers to the improper echo signals that appear as artifacts in the ultrasound images, which can obscure the true anatomical structures or alter the representation of blood flow. By increasing the wall filter, the ultrasound machine limits its sensitivity to low-frequency signals that are often responsible for these ghosting artifacts. The wall filter essentially enhances the system's ability to distinguish between the desired signals, such as those coming from moving blood, and unwanted low-frequency echoes that can contribute to ghosting.

This technique is particularly useful in Doppler imaging, where the goal is to accurately assess blood flow. By eliminating low-frequency noise, the image clarity improves, making it easier to identify actual blood flow patterns without the interference of ghosting effects.