High-resolution CT of idiopathic interstitial pneumonias

Important recent changes have occurred in the understanding of idiopathic interstitial pneumonias. Idiopathic pulmonary fibrosis (IPF) (characterized histologically as usual interstitial pneumonia) is recognized as a progressive disease with a relatively poor prognosis and with a characteristic CT appearance. Nonspecific interstitial pneumonia has a better prognosis than IPF and has ground-glass attenuation as its salient CT feature. Cryptogenic organizing pneumonia is characterized on CT by consolidation and ground-glass attenuation. Acute interstitial pneumonia is the idiopathic form of adult respiratory distress syndrome. The less common entity of desquamative interstitial pneumonia is characterized by ground-glass attenuation.