Kerley lines

Thin, peripheral linear pulmonary opacities on chest radiograph, typically located at the lung bases and perpendicular to the pleural surface, representing thickened or fluid-filled interlobular septa due to interstitial infiltration, edema, or fibrosis.

Causes

• Interstitial pulmonary edema

  • Left-sided heart failure

  • Cardiogenic pulmonary edema

  • Fluid overload

  • Renal failure causing volume retention

• Pulmonary interstitial diseases

  • Interstitial pulmonary fibrosis

  • Idiopathic pulmonary fibrosis

  • Nonspecific interstitial pneumonia

  • Sarcoidosis

• Malignant causes

  • Lymphangitic carcinomatosis

  • Metastatic cancer involving pulmonary lymphatics

  • Lymphoma affecting the interstitium

• Infectious and inflammatory causes

  • Viral pneumonia

  • Atypical pneumonia

  • Tuberculosis

  • Inflammatory interstitial lung disease

• Other causes

  • Pneumoconiosis

  • Sarcoid-like granulomatous diseases

  • Lymphatic obstruction

  • Pulmonary venous hypertension

  • Drug-induced interstitial lung disease

  • Radiation-induced lung injury