Mirror image artifacts in color Doppler imaging most commonly occur when what condition is present?

• A. Near-field clutter
• B. Color map inversion
• C. Focal depth is too shallow
• D. Highly reflective plaques distant from the transducer are insonated

Answer: (D)

Mirror image artifacts come from a strong reflector in the beam path acting like a mirror, causing a duplicate of the color Doppler signal to appear on the opposite side of that reflector. When there are highly reflective plaques that are distant from the transducer but still insonated, they can reflect the ultrasound waves and generate a ghost image of the flow across the plaque. This makes the color signal look like a second vessel or flow on the far side, which is the classic mirror artifact. Other issues, like near-field clutter, color map inversion, or shallow focal depth, produce different appearance problems and don’t create the characteristic mirror copy across a strong reflector.