The American Thoracic Society-European Respiratory Society classification of idiopathic interstitial pneumonias (IIPs), published in 2002, defines the morphologic patterns on which clinical-radiologic-pathologic diagnosis of IIPs is based. IIPs include seven entities: idiopathic pulmonary fibrosis, which is characterized by the morphologic pattern of usual interstitial pneumonia (UIP); nonspeci...

R adiographic studies (Figs 1–4) were obtained from a 60-year-old man with recurrent pneumonias for the past 15 years. He has chronic foulsmelling sputum, increasing shortness of breath, and increasing supplemental oxygen requirements. He reports a 50–pack-year history of tobacco use, but has not smoked for 12 years. In addition to bilateral crackles and rhonchi posteriorly, he exhibits digital...