Septic pulmonary emboli

Septic pulmonary emboli refer to the embolization of infectious particles (intravascular thrombus containing microorganisms) into the lungs via the pulmonary arterial system. 

Symptoms can be not specific but most manifest as a bacteremia 18 with, dyspnea, chest pain, cough and other respiratory symptoms. Often concurrent symptoms of the extrapulmonary primary infective focus are also present.

Septic emboli can originate from different sources 5:

The clinical context is significant in image interpretation and differential considerations. Most patients will be clinically septic and have positive blood cultures at the time of imaging assessment.

Chest x-ray features are nonspecific but may show 3:

  • peripheral, lower lobe predominant infiltrative densities: can be unilateral or bilateral
  • diffuse bilateral nodular densities (often poorly marginated) in varying stages of cavitation
    • these nodules generally range between 1-3 cm
    • the nodules vary greatly in size, which is a reflection of repeated episodes of embolic shower 15
    • may increase in number or change in appearance (size or degree of cavitation) on subsequent short-term follow up radiographs 12
  • accompanying small pleural effusions can be common
  • features suggestive of complicating pleura empyemas may be seen

Bilateral abnormalities may be present in as much as 80% of cases 18.

  • feeding vessel sign 9: peripheral nodules with clearly identifiable feeding vessels associated with lung abscesses 2,3
  • subpleural nodular lesions or wedge-shaped densities with or without necrosis caused by septic infarcts (these can manifest as cavitary pulmonary infarcts)
    • these may have a dependent, lower zone predication 13,15
    • the wedge-shaped lesions usually range between 10-20 mm 6
    • peripheral nodular densities usually range between 5-35 mm 7

Recognized complications include:

For small and/or different size cavitary lung lesions on HRCT or CT chest, consider:

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Article information

rID: 22848
System: Chest
Tag: cases, cases
Synonyms or Alternate Spellings:
  • Pulmonary septic emboli
  • Septic pulmonary embolus
  • Septic emboli - lung
  • Septic emboli to lung
  • Septic emboli to the lung
  • Septic emboli to the lungs
  • Septic pulmonary embolism
  • Septic lung embolism
  • Septic pulmonary embolization (SPE)
  • Septic pulmonary embolization
  • Septic pulmonary embolisation
  • Septic pulmonary embolisation (SPE)
  • Septic embolism to the lungs
  • Septic embolism to the lung
  • Septic embolism to lungs
  • Septic embolism to lung
  • Septic PE
  • Lung septic emboli
  • Lung septic embolus
  • Septic pulmonary emboli (SPE)

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Cases and figures

  • Case 1
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  • Case 2: complicated by a pneumothorax
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  • Case 3
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  • Case 4
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  • Case 5
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  • Case 6
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  • Case 7: with chest wall abscess
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  • Case 8
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