Table 1.

HRCT criteria for UIP pattern.

UIP PATTERN	POSSIBLE UIP PATTERN	INCONSISTENT WITH UIP PATTERN
(All four features)	(All three features)	(Any of these seven features)
• Subpleural, basal predominance	• Subpleural, basal predominance	• Upper or mid-lung predominance
• Reticular abnormality	• Reticular abnormality	• Peribronchovascular predominance
• Honeycombing with or without traction bronchiectasis	• Absence of features listed as inconsistent with UIP pattern (see third column)	• Extensive ground glass abnormality (extent > reticular abnormality)
• Absence of features listed as inconsistent with UIP pattern		• Extensive ground glass abnormality (extent > reticular abnormality)
		• Discrete cysts (multiple, bilateral, away from areas of honeycombing)
		• Diffuse mosaic attenuation/air-trapping (bilateral, in three or more lobes)
		• Consolidation in bronchopulmonary segment(s)/lobe(s)

Abbreviations: HRCT, high-resolution computed tomography; UIP, usual interstitial pneumonia.