In radiology, the<unk>  is a finding on chest radiograph and computed tomography that is crescenteric and radiolucent, due to a lung cavity that is filled with<unk>  and has a round radiopaque mass. Classically, it is due to an aspergilloma, a form of aspergillosis, that occurs when the fungus Aspergillus grows in a cavity in the lung. It is also referred as Monad sign.
Air crescent sign
Crescent sign
Silhouette sign
Fat pad sign
Schwartz sign
Crichton-Browne sign
Seidel sign
Von Graefe's sign