Pulmonary plethora

Dr Vincent Tatco and Dr Henry Knipe et al.

Pulmonary plethora is a term used to describe the appearances of increased pulmonary perfusion on chest radiographs. It is commonly used in paediatric radiology. 

Usually a left-to-right shunt of 2:1 is required for pulmonary plethora to occur 2,3. Increased pulmonary perfusion occurs in a number of situations 1,2:

It may also been seen in healthy patients with increased cardiac output (e.g. pregnancy) 3

Plain radiograph
  • prominent pulmonary vasculature
    • pulmonary vessels are dilated and tortuous extending farther into the peripheral one-thirds of the lungs
    • diameter of a pulmonary artery is greater than the accompanying bronchus
  • increased size of number of hilar pulmonary arteries
    • >3-5 end-on should be seen
    • diameter of the right descending pulmonary artery is bigger than the diameter of the trachea
  • cardiomegaly may be present

Pulmonary plethora can occur with or without cyanosis with different causes attributed 3,4:

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Article information

rID: 41136
Systems: Chest, Paediatrics
Section: Signs
Synonyms or Alternate Spellings:
  • Increased pulmonary vascularity
  • Increased pulmonary perfusion

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Cases and figures

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    Case 1: with VSD
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    Case 2: with VSD
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    Case 3: with AVSD
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    Mild cardiomegaly...
    Case 4: with TAPVR
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    Case 5: with truncus arteriosus
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    Case 6: with PDA
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