Uncategorized

• • Anatomical Basis:
    • Refers to abnormalities involving the pulmonary fissures, which are thin layers of connective tissue separating the lung lobes.
    • The major (oblique) fissures separate the upper and lower lobes, while the minor (horizontal) fissure separates the right upper and middle lobes.
    • Pulmonary lymphatic vessels run along the fissures, particularly at their edges, where they facilitate drainage from the pleura and lung parenchyma.
    • Diseases affecting lymphatic tissue, such as sarcoidosis or lymphatic metastases, can manifest as nodular thickening along the fissures.
  • Radiological Characteristics:
    • On Chest X-ray (CXR):
      • Fissures may appear more prominent or displaced if thickened or under tension.
      • Nodular or irregular opacities along fissures may indicate lymphatic or inflammatory involvement.
    • On Chest CT:
      • Fissural Thickening:
        • Smooth thickening: commonly associated with fluid (e.g., pleural effusion, congestive heart failure).
        • Nodular thickening: can indicate lymphatic involvement, as seen in sarcoidosis or metastatic disease.
      • Nodularity Along Fissures:
        • Sarcoidosis: Often shows nodules along the fissures due to granulomas involving lymphatic channels.
        • Lymphoma or Metastases: May present as discrete nodules or irregular masses.
      • Fissural Displacement:
        • Altered fissure position due to volume loss (atelectasis) or increased lung volume (hyperinflation or mass effect).
      • Air or Fluid Collection:
        • Subfissural cysts, pneumothorax, or subpulmonic effusions.
  • Common Diseases and Conditions Associated:
    1. Lymphatic Involvement:
       • Sarcoidosis: Perilymphatic nodules that may involve fissures and adjacent pleura.
       • Lymphatic metastases: Spread of malignancy along lymphatic pathways causing fissural nodularity.
       • Lymphangitic carcinomatosis: Diffuse lymphatic involvement leading to irregular fissural thickening.
    2. Pleural or Subpleural Pathology:
       • Pleural effusion (subpulmonic or along fissures).
       • Pneumothorax extending into the fissures.
    3. Fibrosis and Scarring:
       • Interstitial fibrosis involving the subpleural areas, with traction on the fissures.
       • Post-infectious or post-surgical changes.
    4. Mass Lesions:
       • Metastatic deposits or pleural-based tumors (e.g., mesothelioma).
    5. Congenital or Structural Variations:
       • Accessory fissures or incomplete fissures.
       • Congenital cysts near fissures.
    6. Trauma:
       • Hemorrhage or hematoma in the fissure following chest trauma.
    7. Infections:
       • Empyema or abscess near the fissure.
       • Subfissural pneumonia or organizing pneumonia.
  • Clinical Relevance:
    • Fissural findings may indicate underlying disease such as pleural effusion, infection, lymphatic involvement, or malignancy.
    • Nodular thickening along fissures often correlates with lymphatic diseases like sarcoidosis or lymphangitic carcinomatosis.
    • Radiological identification of fissural abnormalities is crucial for diagnosing systemic diseases affecting the pleura and lymphatics, differentiating between infectious, neoplastic, or inflammatory causes