• Common medical problem, related to smoking
  
• Centriacinar most common, other types: panlobular, paraseptal, irregular
  
• Chest radiography insensitive for mild disease
  
• Centriacinar predominately involves upper lung zones
  
• Panlobular predominately involves lower lung zones

Chest radiography

• Hyperinflation
  
  • flat diaphragms
    
  • widened retrosternal air space
    
  • lung height increased
    
  • small narrow heart
    
• Parenchymal areas of hypoattenuation
  
  • inhomogeneous distribution
    
  • arterial deficiency, increased branching angle of remaining vessels
    
  • bullae
    
  • “increased marking” not clearly understood, combination of bronchial wall thickening or superimposition of emphysematous walls
    
• Secondary manifestations
  
  • Pulmonary artery hypertension
    
    • enlarged central pulmonary arteries and peripheral arterial pruning
      
• Sensitivity poor for early disease, rare false positives
  
  • problem is recognition of loss of normal lung
    
  • normal lung at chest radiography is 90% air, making detection of slight increases in air nearly impossible
    
• Crude correlation between indices of airway obstruction and radiographic findings

CT/HRCT

• More sensitive than chest radiography
  
• Emphysematous holes usually have no discernable wall
  
• Central artery may remain visible surrounded by destroyed lung
  
• Objectively measured by assuming that lung with a threshold HU < -960 is emphysematous lung
  

• Technical: false negatives with low dose technique or wide windows
  
• Asthma
  
• Contrictive Bronchiolitis Obliterans
  
• Athletic hyperinflation

• Abnormal enlargement of the airspaces distal to the terminal bronchioles accompanied by destructive changes of the alveolar walls without obvious fibrosis
  
• Emphysema usually inhomogeneous
  
• centriacinar emphysema strongly associated with cigarette smoking
  
• Centriacinar: dilatation 2nd order respiratory bronchioles in secondary lobule
  
• Panlobular: involves entire lobule

• Dyspnea, shortness of breath
  
• Obstructive pulmonary function tests
  
• Treatment
• smoking cessation
  
• Bronchodilators
  
• Pneumococcus vaccination
  
• Lung volume reduction surgery (criteria, inhomogeneous distribution upper lung zones
• Lung Transplant

Stern EJ et al: CT of the lung in patients with pulmonary emphysema: Diagnosis, quantification, and correlation with pathologic and physiologic findings. AJR 162: 791-8, 1994.