CT Diagnostic Criteria For UIP
CT Diagnostic criteria for UIP
Thoracic high resolution CT scan is the first line test for diagnosing ILD and idiopathic pulmonary fibrosis (IPF).
In about 50% of cases, the thoracic HRCT shows a characteristic usual interstitial pneumonia (UIP) pattern, supporting the IPF diagnosis without performing lung biopsy in an appropriate clinical context.
For a CT to suggest UIP, a certain number of CT criteria must be met according to an official ATS/ERS/JRS/ALAT clinical pratice guideline.
Subpleural and basal
- Distribution is often heterogeneous
Variants of distribution: occasionally diffuse, may be asymmetrical
Honeycombing
- With or without traction bronchiectasis or bronchiolectasis
Possibly superimposed mild ground-glass opacities, reticular pattern, pulmonary ossification
Subpleural and basal predominance of anomalies
- Distribution is often heterogeneous
Reticular pattern with peripheral
- traction bronchiectasis or bronchiolectasis
May have mild ground-glass opacities
Subpleural and basal predominant
- Subtle reticulation
may have mild ground-glass opacities or distortion
(“early UIP pattern”)
CT features and/or distribution of lung fibrosis that do not suggest any specific etiology (“truly indeterminate”)
Predominant distribution
- Peribronchovascular
- Perilymphatic
- Upper or mid-lung
CT features:
- Cysts
- Marked mosaic attenuation
- Predominant GGO
- Profuse micronodules
- Centrilobular nodules
- Nodules
- Consolidation
Orientation to a secondary pulmonary fibrosis
- Pleural plaques (asbestosis)
- Dilated esophagus (CTD)
- Distal clavicular erosions (RA)
- Extensive lymph node enlargement
- Pleural effusions, pleural thickening (CTD/drugs)