IPF diagnostic criteria based on HRCT and lung biopsy
| UIP pattern on HRCT | Histopathological criteria for UIP in IPF* | ||||
| Lung biopsy not available or non-diagnostic | Definite UIP-IPF | Probable UIP-IPF | Indeterminate UIP-IPF | Features most consistent with an alternative diagnosis | |
| Typical | Eligible | Eligible | Eligible | Eligible | Ineligible |
| Probable, age >60 years | Eligible | Eligible | Eligible | Eligible | Ineligible |
| Probable, age ≤60 years | Ineligible | Eligible | Eligible | Ineligible | Ineligible |
| Indeterminate | Ineligible | Eligible | Eligible | Ineligible | Ineligible |
| Most consistent with non-IPF diagnosis | Ineligible | Ineligible | Ineligible | Ineligible | Ineligible |
*Adapted from Chung et al39 and Lynch et al.4
HRCT, high-resolution CT; IPF, idiopathic pulmonary fibrosis; UIP, usual interstitial pneumonia.