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Egyptian Board Thoracic Diseases study materials
Egyptian Board Thoracic Diseases study resources

Egyptian Board Thoracic Diseases: Pulmonary Diagnostic Procedures and Imaging

Egyptian Board Thoracic Diseases · Work through your exam, one topic at a time.

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Pulmonary Diagnostic Procedures and Imaging

Domain 2 - Pulmonary Diagnostic Procedures and Imaging

This domain examines whether you can choose and interpret pulmonary function tests, arterial gases, chest imaging and bronchoscopic sampling. The Board favours pattern recognition plus technical caveats: when spirometry is acceptable, when a bronchodilator response is significant, what a tree-in-bud CT pattern means, and when EBUS-TBNA is preferred over blind biopsy.

Core rules

  • Spirometry is acceptable with a good start, no cough in the first second, and reproducibility within 150 mL. Obstruction is FEV₁/FVC below 0.70 (or below the lower limit of normal); restriction is suggested by low FVC with a preserved ratio and confirmed by low TLC.
  • A significant bronchodilator response in adults is both ≥12% and ≥200 mL increase in FEV₁ or FVC. It supports asthma but does not exclude COPD.
  • DLCO is reduced in emphysema, interstitial disease, pulmonary vascular disease and anaemia; it may be normal or high in asthma and obesity.
  • HRCT patterns: UIP has honeycombing, traction bronchiectasis and basal/peripheral reticulation; tree-in-bud indicates small-airway infection or aspiration; centrilobular nodules suggest hypersensitivity pneumonitis or bronchiolitis.
  • EBUS-TBNA is first-line for mediastinal nodal staging and central lesions; transbronchial cryobiopsy may be used for diffuse parenchymal disease when MDT review cannot diagnose.

Worked example

A 55-year-old smoker has pre-bronchodilator FEV₁ 1.40 L, FVC 2.80 L (ratio 0.50); post-bronchodilator FEV₁ 1.62 L, FVC 2.95 L (ratio 0.55). The FEV₁ rise is 220 mL, or 15.7%, so the bronchodilator response is significant. The ratio remains below 0.70, so obstruction persists. DLCO is 60% predicted. The combined picture is persistent airflow obstruction with a significant reversible component and reduced gas transfer, consistent with COPD with emphysema; asthma alone would usually have a normal DLCO. Management includes inhaled bronchodilators, smoking cessation and vaccination, not a fixed-label diagnosis based on reversibility alone.

Traps that cost marks

  • Using the fixed FEV₁/FVC ratio alone in an elderly patient without considering the lower limit of normal.
  • Accepting a 10% FEV₁ rise as a bronchodilator response when the absolute rise is under 200 mL.
  • Ordering HRCT instead of CT pulmonary angiography for suspected acute PE.
  • Treating a positive IGRA or a single culture as immediate proof of active tuberculosis without clinical and radiological correlation.

Key points

  • Obstruction: FEV₁/FVC <0.70; restriction: low FVC with preserved ratio, confirmed by low TLC.
  • Bronchodilator response requires ≥12% and ≥200 mL change.
  • DLCO helps separate emphysema from asthma and detects gas-transfer limitation.
  • HRCT UIP pattern: honeycombing, traction bronchiectasis, basal-peripheral predominance.
  • EBUS-TBNA is preferred for mediastinal nodal sampling.