Comet tail sign
ChestCT
A curvilinear band of vessels and bronchi sweeps into the hilum from a peripheral rounded pleural-based mass, resembling a comet's tail.
What it means
Rounded atelectasis, a benign folded region of collapsed lung tethered to adjacent pleural disease.
Mechanism
Pleural fibrosis and contraction fold and swirl the underlying lung, dragging bronchovascular bundles into a curving tail toward the hilum.
Associated conditions
- Rounded atelectasis
- Asbestos-related pleural disease
- Chronic pleural effusion
- Empyema or haemothorax sequelae
Pearls
- Adjacent pleural thickening and volume loss support a benign diagnosis and help avoid biopsy.
- The mass abuts thickened pleura and typically enhances like normal lung.
References
- Radiopaedia: Comet tail sign (rounded atelectasis)
For educational use only. This dictionary is a study aid and reference, not a diagnostic tool, and must not be used to guide clinical decisions or patient care. Imaging appearances vary; always correlate with the full clinical picture and confirm with a qualified radiologist.