Signet ring sign is seen in: March 2013: (A) Blastomycosis, (B) Bronchogenic carcinoma, (C) Invasive aspergillosis, (D) Bronchiectasis
Answer is D. Ans. D i.e. Bronchiectasis Signet ring sign The signet ring sign is a CT finding seen in patients with Bronchiectasis The ring of soft-tissue attenuation represents the wall of the dilated bronchus seen on a cross-sectional CT scan, whereas the low-attenuating circle of air represents air within the dilated bronchus. The circle of soft-tissue attenuation abutting the ring represents a cross-sectional image of the pulmonary aery that lies adjacent to the dilated bronchus.