Air crescent sign in chest X-ray is seen in: September 2010

Ans. C: Invasive Angioinvasive aspergillosis is the most severe and aggressive form of invasive aspergillosis and is seen only in profoundly immunocompromised patients and is a life threatening condition requiring prompt treatment. Typical appearances are those of solitary or multiple pulmonary nodules or masses. Wedge-like areas of ill-defined opacity may also be seen most likely representing infarcts due to invasion of proximal pulmonary vessels. An air crescent may be visible, although it is seen earlier on CT.