Abstract
Abstract only Introduction: Diffuse pulmonary ossification (DPO), or “dendriform” ossification, occurs in the setting of chronic lung disases, particularly usual interstitial pneumonitis (UIP). It also can occur in assocation with severe emphysema or chronic lung infections. We have observed DPO on chest CT in the absence of chronic lung disease. Objectives: We attempt to identify a cohort of individuals with CT findings of DPO in isolation in order to a) characterize the imaging appearance and b) assess potential clinical factors that may be associated with the development of DPO. Methods: We performed an elctronic search of chest CT reports between 2000-2011 at our institution for the word “dendriform” The CT studies were then reviewed by 3 thoracic imaging subspecialists who characterized the findings. Electronic medical records were reviewed for demographic and clinical information and follow-up data. Results: 25 patients with CT findings of DPO in isolation were identified. DPO showed dense and soft tissue nodularity involving the peripheral interstitium (interlobular septae and subpleural space) especially in the posterior and lateral lower lungs with a costophrenic angle predominance. Patients were male, over age 70, and had few if any pulmonary symptoms. Smoking history was variable. Many had a history of or risk factors for aspiration. Serial scans, when available, showed progression of DPO over many years with minimal clinical change. Conclusions: DPO can occur in isolation with a characteristic CT appearance, particularly in elderly men. It may indicate recurrent chronic aspiration in some cases. The findings progress over time with minimal clinical symptoms.