comet tail sign

com·et tail sign

in chest radiology, the curved appearance of pulmonary arteries and veins associated with rounded atelectasis, fibrosis associated with organizing pleurisy.
Synonym(s): comet sign
Imaging Blood vessels Comet tail sign A term referring to the CT appearance of a tapering, noncalcified vein, adjacent to a rounded phlebolith, which serves to differentiate it from a stone in the ureter
Imaging Gallbladder A term referring to reverberation artifacts seen by ultrasonography within a thickened wall of the gallbladder, strongly suggesting small cholesterol crystals within Rokitansky-Aschoff sinuses in adenomyomatosis, which is usually asymptomatic. Air in emphysematous cholecystitis may produce a similar picture, but in contrast to patients with cholesterol crystals, those with emphysematous cholecystitis are clinically unwell
Imaging Lung Parachute sign A focal area of collapsed lung adjacent to pleural thickening with distortion of blood vessels, which is seen as a curvilinear soft tissue density on a plain chest film, which extends from the lateral pleura to the hilum (this image is more parachute-like, given the multiple ‘tails’); the sign is due to contracted fibrous scarring and shrinking pleuritis with rounded atelectasis, and seen in the folded lung syndrome
References in periodicals archive ?
(10) The ultrasonographic feature of pulmonary fibrosis consists of detection and quantification of the US lung comet tail sign (B-line artifacts); this sign is generated by the reflection of the US beam from the thickened subpleural interlobar septum.
The lung surface can be easily investigated by TTUS, so the comet tail sign "artifacts" are quickly detectable with small surface high frequency probe.
B, The comet tail sign (two B-lines in the mild form of interstitial pulmonary fibrosis.