Focal interstitial pulmonary fibrosis refers to a manifestation of pulmonary fibrosis where changes are confined and localised to a small region of the lung, they can arise from a range of aetiologies with one rather common example being osteophyte induced adjacent pulmonary atelectasis and fibrosis.
Radiographic features
HRCT chest
Can be variable ranging from localised reticular markings to regions of non-dependant atelectasis to small focal ground-glass nodules 1.