• is an obstructive lung disease
  • Caused by
    •  infection
    • pneumonia
    • TB aspergillosis
    • smoking
    • radiation therapy
    • cystic fibrosis
    • immune disease
      • autoimmune
      • HIV/AIDS
  • Resulting in
    • permanent enlargement of parts of the airways

Bronchiectasis refers to irreversible, abnormal dilation of the bronchial airways due to chronic inflammation, infection, or structural airway damage. It disrupts normal bronchial function, leading to impaired mucus clearance, recurrent infections, and airflow obstruction. A specific subtype, traction bronchiectasis, occurs due to fibrosis or scarring of the surrounding lung parenchyma, which pulls the airways open.

Radiological imaging, particularly high-resolution CT (HRCT), is critical for diagnosing and differentiating bronchiectasis subtypes, including traction bronchiectasis.

---

Radiological Features

1. Chest X-Ray (CXR):
   • Findings:
     • Thickened bronchial walls visible as tram-track lines (parallel linear opacities).
     • Ring shadows representing cross-sectional dilated bronchi.
     • Increased lung markings or scarring in advanced cases.
   • Limitations:
     • CXR has low sensitivity for detecting bronchiectasis, particularly traction bronchiectasis.
2. High-Resolution CT (HRCT):
   • Gold Standard for diagnosing and characterizing bronchiectasis.
   • Key Findings:
     1. Bronchial Dilation:
        • Bronchi larger than the accompanying pulmonary arteries (signet ring sign).
     2. Lack of Tapering:
        • Abnormal bronchi extend to the lung periphery without normal tapering.
     3. Bronchial Wall Thickening:
        • Reflects chronic inflammation.
     4. Mucus Plugs:
        • Internal airway opacities often seen in post-infectious or obstructive cases.

Traction Bronchiectasis (HRCT Findings)

 

Chronic MAC Infection

Cystic Bronchiectasis and Cicatricial Atelectasis

 

1.  

1. • Cause:
     • Secondary to fibrotic processes that exert pulling forces on the airways, leading to dilation.
   • Associated Conditions:
     • Interstitial lung diseases (ILD):
       • Especially idiopathic pulmonary fibrosis (IPF), sarcoidosis, or chronic hypersensitivity pneumonitis.
     • Radiation-induced fibrosis or post-inflammatory scarring.
   • Imaging Features:
     • Irregularly dilated bronchi located in regions of fibrotic changes.
     • Often associated with honeycombing, ground-glass opacities, or architectural distortion.
     • Peripherally distributed in fibrotic diseases, often near subpleural regions.
2. MRI:
   • Rarely used but can evaluate bronchiectasis and mucus plugging, especially in cystic fibrosis patients.

---

Classification

1. Morphological Types (on HRCT):
   • Cylindrical:
     • Uniformly dilated bronchi resembling tubes; common in post-infectious bronchiectasis.
   • Varicose:
     • Irregularly dilated bronchi with alternating areas of dilation and narrowing; seen in chronic infections.
   • Cystic (Saccular):
     • Severely dilated bronchi forming cyst-like structures, associated with advanced disease.
   • Traction:
     • Bronchiectasis caused by fibrotic retraction of surrounding lung tissue.
2. Distribution:
   • Localized:
     • Limited to one lobe or segment (e.g., post-obstructive bronchiectasis).
   • Diffuse:
     • Involves multiple lobes, often seen in systemic diseases or infections (e.g., cystic fibrosis, ILD).

---

Causes and Associations

1. Post-Infectious:
   • Common in tuberculosis, pertussis, measles, or necrotizing bacterial infections.
2. Interstitial Lung Diseases (Traction Bronchiectasis):
   • Idiopathic Pulmonary Fibrosis (IPF):
     • Classically associated with subpleural honeycombing and traction bronchiectasis.
   • Sarcoidosis:
     • Granulomatous inflammation leading to fibrosis and airway distortion.
   • Chronic Hypersensitivity Pneumonitis:
     • Causes peripheral fibrosis with traction bronchiectasis.
3. Cystic Fibrosis:
   • Common cause of diffuse bronchiectasis.
4. Obstructive:
   • Airway obstruction from foreign bodies, tumors, or mucus plugging.
5. Congenital Disorders:
   • Kartagener’s syndrome (primary ciliary dyskinesia), Williams-Campbell syndrome.

---

Complications

1. Recurrent Infections:
   • Leads to progressive lung damage.
2. Hemoptysis:
   • Due to erosion of bronchial blood vessels.
3. Respiratory Failure:
   • Advanced disease with airflow obstruction.
4. Pulmonary Hypertension:
   • Rare, due to chronic hypoxia.

---

Clinical Relevance

Including traction bronchiectasis highlights the importance of recognizing fibrotic processes that distort airway anatomy. Identifying the pattern and distribution of bronchiectasis (e.g., traction vs. inflammatory) on imaging is essential for targeting treatment and evaluating prognosis.

Apical Bronchiectasis – Possibly TB

• Emphysema
• Smoking and Bronchiectasis –
  • • Loss of ciliary function by cigarette smoke
    • Increase mucus production with decrease clearing
    • Increase infection

Saccular Bronchiectasis

 

Mucus Filled airway with Distal Hyperinflation

 

Bronchiectasis and Atelectasis

 

Compare the two Sides

Links and References

Milliron B, et al Bronchiectasis: Mechanisms and Imaging Clues of Associated Common and Uncommon Diseases RadioGraphicsVol. 35, No. 4 2015

 

• ,

Brent P. Little

• TCV
  • Bronchiectasis
    • 032Lu Bronchiectasis and Emphysema
    • 034Lu Basal Bronchitis Bronchiectasis Young Female
    • 044Lu Chronic Inactive TB  Lymphatic Distribution
    • 003MC  Kartagener’s and Bronchiectasis
    • 054 LU Right Middle Lobe Syndrome – Bronchiectasis probable TB
    • 063LU Sarcoidosis and Bronchiectasis
    • 72LU TB and Bronchiectasis
    • 73Lu TB Bronchiectasis

Kartagener’s syndrome TCV page

Fleischner Society

Pathology.—Bronchiectasis is irreversible localized or diffuse bronchial dilatation, usually resulting from chronic infection, proximal airway obstruction, or congenital bronchial abnormality (^,26). (See also traction bronchiectasis.)

Radiographs and CT scans.—Morphologic criteria on thin-section CT scans include bronchial dilatation with respect to the accompanying pulmonary artery (signet ring sign), lack of tapering of bronchi, and identification of bronchi within 1 cm of the pleural surface (^,27) (^,Fig 11). Bronchiectasis may be classified as cylindric, varicose, or cystic, depending on the appearance of the affected bronchi. It is often accompanied by bronchial wall thickening, mucoid impaction, and small-airways abnormalities (^,27–^,29). (See also signet ring sign.)