Comet Tail Artefacts
Comet tail artefacts are seen where reverberation occurs within a small, but highly reflective object. This short path reverberation produces a series of closely spaced echoes, giving a characteristic banded appearance.
These fleeting artefacts are seen from the pleura, or when scanning over regions of bowel gas. In this image a tissue plane is causing the artefact.
Comet tail artefacts are useful in seeing that the visceral pleura is opposed to the parietal pleura. Absence suggests pneumothorax.