Pediatric Pulmonary Fat Embolism

  • Etiology: Fat particles are released from bone marrow after lower extremity fractures or orthopedic surgery and enter blood circulation and embolize and mechanically obstruct pulmonary capillaries and incite a secondary inflammatory reaction to their free fatty acids
  • Imaging CT: 3 patterns commonly seen:
    — Ground-glass opacity with geographic distribution
    — Ground-glass opacity with interlobular septal thickening
    — Nodular opacities
    — Note: Fatty filling defects in pulmonary arteries are rarely seen
  • DDX: Acute respiratory distress syndrome
  • Complications: Usually none
  • Treatment: Supportive care
  • Clinical: Usually occurs in association with long bone fractures

Radiology Cases of Pulmonary Fat Embolism

CT of pulmonary fat embolism
AP radiograph of the right femur (left) and lateral radiograph of the right tibia and fibula (middle) show comminuted fractures of the femur, tibia, and fibula. Axial (above right and middle right) and coronal (below right) CT with contrast of the chest shows a geographic distribution of ground glass opacities throughout both lungs.
CXR of pulmonary fat embolism
CXR AP shows diffuse nodular infiltrates throughout the lungs, right greater than left.