Table 1.

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.