CT scan of a<unk>  in a patient with COPD A<unk>  also known as scabbard<unk>  is a<unk>  that has an abnormal shape. The posterior area of the<unk>  increases in diameter while the lateral measurement decreases.
Saber-sheath trachea
Bird fancier's lung
Bio-secure bubble
Metsovo lung
Farmer's lung
Tracheoinnominate fistula
Subglottic stenosis
Cramp-ring