Air Crescent Sign on Chest CT • Crescentic or circumferential rim of radiolucent airspace within a parenchymal consolidation or nodular opacity • DDx: Invasive aspergillosis, bronchogenic Ca, PJP https://doi.org/10.1016/j.chest.201 #Air #Crescent #Sign #CT #Lung #Pulmonary #diagnosis #radiology #clinical