Table. 2—

Distinguishing clinical and radiographical features of idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia

Idiopathic pulmonary fibrosisNonspecific interstitial pneumonia
Duration of illnessChronic (>12 months)Subacute to chronic
Frequency of diagnosis47–64%14–36%
TreatmentPoor response to any treatmentCorticosteroid responsiveness
Prognosis50–70% mortality within 5 yrs<15% mortality in 5 yrs
Chest radiographBilateral reticular opacities in lower zones; volume loss plus honeycombingBilateral hazy and reticular opacity
HRCTPeripheral, subpleural, basal predominance; reticular opacities; honeycombing; traction bronchiectasis; architectural distortionPeripheral, basal, symmetrical; ground-glass attenuation; consolidation; traction bronchiectasis; lower lobe volume loss
Key histological featuresUIP patternNSIP pattern: cellular, fibrotic
  • HRCT: high-resolution computed tomography; UIP: usual interstitial pneumonia; NSIP: nonspecific interstitial pneumonia.