You are imaging a fluid-filled structure that has equidistant horizontal bands appearing in the near field. The bands have decreasing brightness with depth. What artifact are you imaging?

• A. Slice thickness
• B. Side lobes
• C. Reverberation
• D. Comet tail

Answer: (C)

Reverberation artifact is at play here. When the ultrasound pulse bounces back and forth between two strong reflectors—such as the near wall and the far wall inside a fluid-filled structure—echoes are produced at regular depth intervals. Those repeated echoes show up as equidistant horizontal bands in the near field, and their brightness wanes with depth because each successive echo loses energy through attenuation and scattering. This pattern—multiple, evenly spaced, parallel bands with decreasing brightness—is characteristic of reverberation. Other artifacts don’t form this neat, periodic set of bands: side-lobe echoes appear off-axis, slice-thickness artifacts blur structures due to partial-volume effects, and a comet tail looks like a single bright line with a tapering tail rather than a series of evenly spaced bands.