Comet Tail Sign is Seen in?

Comet Tail Sign is seen in Round atelectasis which is a round/oval subpleural opacity in posterolateral pa of lower lobes with converging vessels and airways entering the opacity in a helical fashion usually giving rise to comet tail sign. Flat waist sign is seen in left lower lobe collapse. Golden S sign is seen in right upper lobe collapse due to bronchogenic carcinoma. Spine sign is seen in left lower lobe consolidation. Comet tail sign