pulmonary plethora

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

Pathology

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

• left-to-right cardiac shunts, e.g. ASD, VSD, PDA
• partial or total anomalous pulmonary venous return
• transposition of the great arteries
• truncus arteriosus
• vein of Galen malformation

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

Radiographic features

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 and 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

Practical points

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

• without cyanosis: left-to-right shunt
• with cyanosis: transposition of great arteries, TAPVR, truncus arteriosus

Siehe auch:

• endocardial cushion defect