title: American Thoracic Society-European Respiratory Society Classification of the Idiopathic Interstitial Pneumonias: Advances in Knowledge since 2002.
abstract: In the updated American Thoracic Society-European Respiratory Society classification of the idiopathic interstitial pneumonias (IIPs), the major entities have been preserved and grouped into (a) "chronic fibrosing IIPs" (idiopathic pulmonary fibrosis and idiopathic nonspecific interstitial pneumonia), (b) "smoking-related IIPs" (respiratory bronchiolitis-associated interstitial lung disease and desquamative interstitial pneumonia), (c) "acute or subacute IIPs" (cryptogenic organizing pneumonia and acute interstitial pneumonia), and (d) "rare IIPs" (lymphoid interstitial pneumonia and idiopathic pleuroparenchymal fibroelastosis). Furthermore, it has been acknowledged that a final diagnosis is not always achievable, and the category "unclassifiable IIP" has been proposed. The diagnostic interpretation of the IIPs is often challenging because other diseases with a known etiology (most notably, connective tissue disease and hypersensitivity pneumonitis) may show similar morphologic patterns. Indeed, more emphasis has been given to the integration of clinical, computed tomographic (CT), and pathologic findings for multidisciplinary diagnosis. Typical CT-based morphologic patterns are associated with the IIPs, and radiologists play an important role in diagnosis and characterization. Optimal CT quality and a systematic approach are both pivotal for evaluation of IIP. Interobserver variation for the various patterns encountered in the IIPs is an issue. It is important for radiologists to understand the longitudinal behavior of IIPs at serial CT examinations, especially for providing a framework for cases that are unclassifiable or in which a histologic diagnosis cannot be obtained.
authors.affiliation: From the Section of Diagnostic Imaging, Department of Surgical Sciences, University of Parma, Via Gramsci 14, 43100 Parma, Italy (N.S.); Department of Radiology, National Jewish Health, Denver, Colo (D.A.L.); Department of Radiology, Royal Brompton Hospital, London, England (D.M.H.); Department of Radiology, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, Hyogo, Japan (T.J.); Department of Medicine, University of California-San Francisco, San Francisco, Calif (T.E.K.); and Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY (W.D.T.).
authors.forename: Nicola
authors.initials: N
authors.lastname: Sverzellati
authors.affiliation: From the Section of Diagnostic Imaging, Department of Surgical Sciences, University of Parma, Via Gramsci 14, 43100 Parma, Italy (N.S.); Department of Radiology, National Jewish Health, Denver, Colo (D.A.L.); Department of Radiology, Royal Brompton Hospital, London, England (D.M.H.); Department of Radiology, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, Hyogo, Japan (T.J.); Department of Medicine, University of California-San Francisco, San Francisco, Calif (T.E.K.); and Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY (W.D.T.).
authors.forename: David A
authors.initials: DA
authors.lastname: Lynch
authors.affiliation: From the Section of Diagnostic Imaging, Department of Surgical Sciences, University of Parma, Via Gramsci 14, 43100 Parma, Italy (N.S.); Department of Radiology, National Jewish Health, Denver, Colo (D.A.L.); Department of Radiology, Royal Brompton Hospital, London, England (D.M.H.); Department of Radiology, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, Hyogo, Japan (T.J.); Department of Medicine, University of California-San Francisco, San Francisco, Calif (T.E.K.); and Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY (W.D.T.).
authors.forename: David M
authors.initials: DM
authors.lastname: Hansell
authors.affiliation: From the Section of Diagnostic Imaging, Department of Surgical Sciences, University of Parma, Via Gramsci 14, 43100 Parma, Italy (N.S.); Department of Radiology, National Jewish Health, Denver, Colo (D.A.L.); Department of Radiology, Royal Brompton Hospital, London, England (D.M.H.); Department of Radiology, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, Hyogo, Japan (T.J.); Department of Medicine, University of California-San Francisco, San Francisco, Calif (T.E.K.); and Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY (W.D.T.).
authors.forename: Takeshi
authors.initials: T
authors.lastname: Johkoh
authors.affiliation: From the Section of Diagnostic Imaging, Department of Surgical Sciences, University of Parma, Via Gramsci 14, 43100 Parma, Italy (N.S.); Department of Radiology, National Jewish Health, Denver, Colo (D.A.L.); Department of Radiology, Royal Brompton Hospital, London, England (D.M.H.); Department of Radiology, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, Hyogo, Japan (T.J.); Department of Medicine, University of California-San Francisco, San Francisco, Calif (T.E.K.); and Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY (W.D.T.).
authors.forename: Talmadge E
authors.initials: TE
authors.lastname: King
authors.affiliation: From the Section of Diagnostic Imaging, Department of Surgical Sciences, University of Parma, Via Gramsci 14, 43100 Parma, Italy (N.S.); Department of Radiology, National Jewish Health, Denver, Colo (D.A.L.); Department of Radiology, Royal Brompton Hospital, London, England (D.M.H.); Department of Radiology, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, Hyogo, Japan (T.J.); Department of Medicine, University of California-San Francisco, San Francisco, Calif (T.E.K.); and Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY (W.D.T.).
authors.forename: William D
authors.initials: WD
authors.lastname: Travis
mesh_terms: D001988:Bronchiolitis / Q000000981:diagnostic imaging / Q000209:etiology; D003937:Diagnosis, Differential; D018450:Disease Progression; D006801:Humans; D054988:Idiopathic Interstitial Pneumonias / Q000145:classification* / Q000000981:diagnostic imaging / Q000473:pathology; D008171:Lung Diseases / Q000175:diagnosis; D061330:Multidetector Computed Tomography; D015588:Observer Variation; D012907:Smoking / Q000009:adverse effects