Tracheal stenosis is usually acquired and is caused by intubation or tracheostomy. Inflammation and pressure necrosis of the tracheal mucosa most commonly occur at either the tracheostomy stoma or at the level of the tube balloon. Acute post-intubation stenosis results from mucosal oedema or granulation tissue.
The stenosis is typically 1.5-2.5 cm in length. In patients with chronic stricture, tracheomalacia may result from weakness of tracheal cartilage and can be a cause of dyspnea.
On CT, this condition may be seen as eccentric or concentric soft-tissue thickening internal to normal-appearing tracheal cartilage. The outer tracheal wall has a normal appearance without evidence of deformity or narrowing. Expiratory CT shows little change in tracheal diameter.