CT scans.—Traction bronchiectasis and traction bronchiolectasis respectively represent irregular bronchial and bronchiolar dilatation caused by surrounding retractile pulmonary fibrosis (130). Dilated airways are usually identifiable as such (Fig 69) but may be seen as cysts (bronchi) or microcysts (bronchioles in the lung periphery). The juxtaposition of numerous cystic airways may make the distinction from “pure” fibrotic honeycombing difficult. [Fleischner Society]