In color Doppler, to suppress flash artifact while maintaining flow visibility, which parameter should you adjust?

• A. Increase wall filter
• B. Increase color gain
• C. Increase pulse repetition frequency
• D. Increase line density

Answer: (D)

Focusing on how color data are sampled helps you control flash artifacts without losing real flow signals. Increasing line density means more scan lines are used to form the color box, which boosts spatial sampling and smooths out brief, random color fluctuations caused by noise or tissue motion. This averaging reduces the bright, fleeting color “flashes” while preserving the true Doppler signal of flow, so flow visibility remains intact. Keep in mind that higher line density can lower temporal resolution, but it specifically addresses the flicker issue without altering velocity encoding or gain. Other adjustments either suppress flow information (like wall filter by removing low-velocity signals) or amplify noise (color gain) or change velocity sampling in different ways (PRF), which is why line density is the best choice here.