Incidental Paratracheal Air Cysts on Thoracic CT and Their Association with Chronic Inflammatory Lung Disease

Figure 1

(a) Axial CT scan shows fibrosis and irregular pleural thickening in a left upper lobe. No paratracheal air cyst is visualized. (b) CT scan obtained 57 months later shows a paratracheal air cyst at the right posterior side of the trachea (black line arrow). CT image shows subpleural irregularity in the right upper lobe (black arrow) and progression of fibrosis and bronchiectasis in the left upper lobe (white arrow). The total fibrosis score of both upper lungs increases from 5 to 7 points over the 57 months.

(a)

(b)