Discussion of Comet sign
- The comet sign has been used at CT to aid in the differentiation of a phlebolith from a stone in the ureter.
- The calcified phlebolith represents the comet nucleus and the adjacent, tapering, noncalcified portion of the vein is the comet tail.
- The reliability of the comet sign is not as great as that for the soft-tissue rim sign
 See Also
 External Links
 References for Comet sign
- Raymond B. Dyer, Michael Y. Chen, and Ronald J. Zagoria. Classic Signs in Uroradiology. RadioGraphics 2004 24: S247-280S.