Table 3.
HRCT patterns | |||
UIP | Probable UIP | Indeterminate for UIP | Alternative diagnosis |
Subpleural and basal predominant; distribution is often heterogeneousa | Subpleural and basal predominant; distribution is often heterogeneous | Subpleural and basal predominant | Findings suggestive of another diagnosis, including: |
Honeycombing with or without peripheral traction bronchiectasis or bronchiolectasisb | Reticular pattern with peripheral traction bronchiectasis or bronchiolectasis | Subtle reticulation; may have mild GGO or distortion (“early UIP pattern”) | CT features:
|
May have mild GGO | CT features and/or distribution of lung fibrosis that do not suggest any specific etiology (“truly indeterminate for UIP”) | Predominant distribution Peribronchovascular Perilymphatic Upper or mid-lung |
|
Other:
|
CTD, connective tissue disease; GGO, ground-glass opacity; HRCT, high-resolution computed tomography; IPF, idiopathic pulmonary fibrosis; RA, rheumatoid arthritis; UIP, usual interstitial pneumonia.
Reprinted with permission of the American Thoracic Society.Copyright © 2018 American Thoracic Society. Raghu G, et al. 2018 Diagnosis of idiopathic pulmonary fibrosis. An Official ATS/ERS/JRS/ALAT clinical practice guideline. American Journal of Respiratory and Critical Care Medicine 198:e44-e68. The American Journal of Respiratory and Critical Care Medicine is an official journal of the American Thoracic Society.
Variants of distribution: occasionally diffuse, may be asymmetrical.
Superimposed CT features: mild GGO, reticular pattern, pulmonary ossification.