Idiopathic Pulmonary Fibrosis

Key Facts
  • Unknown cause with poor prognosis
  • Heterogenous fibrosis primarily in the periphery lower lobes
  • Honeycombing and traction bronchiectasis at HRCT
Imaging Findings

Chest radiograph

  • Best imaging clue: Basilar peripheral honeycombing and volume loss
  • Irregular linear opacities in contrast to the granulomatous diseases which are primarily nodular
  • Chest radiography may be normal in spite of symptoms


  • Useful to plan biopsy
  • Spectrum from ground glass opacites to honeycombing
  • Traction bronchiectasis required for confident radiographic diagnosis
  • CT may be normal in mild (or early) disease
  • Subpleural distribution in 80%
  • Mediastinal nodes may be mildly enlarged (nodes < 2 cm diameter)
Differential Diagnosis
  • Asbestosis
  • BOOP
  • Drug reaction
  • Chronic hypersensitivity reaction
  • Sarcoidosis
Pathological Features
  • Unknown insult to alveolar wall and interstitium
  • UIP thought to be repetitive insult vs AIP
  • Usually inhomogeneous both spatially and temporally
  • Fibroblast proliferation
Clinical Presentation
  • Progressive dyspnea, dry cough and fatigue
    • 5th-7th decade, slight predominance in men
  • Treatment
    • Steroids
    • Lung transplant
  • Survival
    • Median 5 years

Hansell DM: Computed tomography of diffuse lung disease: Functional correlates. Eur Radiol 11:1666-80, 2001