Which artifact appears as a series of parallel bands or a solid streak behind a reflector and is associated with a gas bubble?

Which artifact appears as a series of parallel bands or a solid streak behind a reflector and is associated with a gas bubble?

• A. Ring Down
• B. Side Lobes
• C. Comet Tail
• D. Focal Banding

Answer: (A)

Ring-down is produced when gas bubbles in a fluid resonate with the ultrasound beam. That resonance emits a series of echoes that travel back along the beam, creating a bright posterior signal that can appear as parallel bands or a solid streak behind a strong reflector. The presence of gas bubbles makes this pattern distinctive, so the description of a series of parallel bands or a streak behind a reflector aligns with ring-down. Other artifacts described—side lobes show echoes coming from off-axis beams, not a posterior streak; comet tail appears as a single, tapering bright line behind a strong reflector; focal banding is related to beam focusing and appears as bands near the focus—do not match the gas-bubble–associated, multi-band posterior pattern seen with ring-down.

Ring-down is produced when gas bubbles in a fluid resonate with the ultrasound beam. That resonance emits a series of echoes that travel back along the beam, creating a bright posterior signal that can appear as parallel bands or a solid streak behind a strong reflector. The presence of gas bubbles makes this pattern distinctive, so the description of a series of parallel bands or a streak behind a reflector aligns with ring-down.

Other artifacts described—side lobes show echoes coming from off-axis beams, not a posterior streak; comet tail appears as a single, tapering bright line behind a strong reflector; focal banding is related to beam focusing and appears as bands near the focus—do not match the gas-bubble–associated, multi-band posterior pattern seen with ring-down.