Parenchymal bands are a HRCT finding. They can be commonly encountered among patients with asbestosis.
They are typically over 2 cm in length (up to 5 cm), 1-3 mm thick and run through the lung parenchyma and usually extend from a visceral pleural surface . They are formed in a number of ways :
They are thought to reflect pleuroparenchymal fibrosis and are usually associated with distortion of the lung architecture.
- thickening of interlobular septae of a number of adjacent secondary pulmonary lobules
- fibrosis of peribronchovascular interstitium
Parenchymal bands are encountered in a wide range of pulmonary diseases and represent one of the many end-stage fibrotic findings. To mention a few causes:
- asbestosis - found in 60% of patients
- systemic lupus erythematosus
- pulmonary fibrosis
- sequelae of ARDS
- infections including
- pulmonary paracoccidioidomycosis
- Morbus Bechterew
- acute respiratory distress syndrome (ARDS)
- secondary pulmonary lobules
- interlobular septae