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

Figure 2

(a) Axial CT scan shows a paratracheal air cyst () and fibrosis with volume decrease in a right upper lung and subpleural fibrosis in a left upper lung. (b) CT scan obtained 32 months later shows an increase in PAC size. In addition, fibrosis had thickened (arrow) and the volume of the right upper lobe has reduced. Subpleural fibrosis is more prominent in the left upper lung (black line arrow). The total fibrosis score of both upper lungs increased from 9 to 12 points over the 32 months.

(a)

(b)