fallen lung sign(redirected from Ptotic Lung Sign)
fallen lung sign
The radiologic appearance of traumatic transection or rupture of the trachea or a main stem bronchus, consisting of a collapsed lung that seems to dangle from the hilum by only its vascular attachments. Pneumothorax, pneumomediastinum, and subcutaneous emphysema are sometimes seen with tracheobronchial tears.
See also: sign