Pulmonary alveolar edema is a particular pattern of pulmonary edema where most of fluid build up is into the alveolar spaces. The onset of alveolar edema may also be associated with direct pressure-induced damage to the alveolar epithelium. It can sometimes have a central peri-hilar pattern. Alveolar pulmonary edema often preceded by interstitial pulmonary edema and usually develops once the pulmonary venous pressure exceeds 30 mmHg 2.
On chest radiographs, there are often bilateral opacities that demonstate extend in a fan shape outward from the hilum in a ‘batwing’ pattern. With worsening alveolar edema, the lung opacification can become increasingly homogenous. Air bronchograms can be seen with alveolar edema 2.
- 1. Gluecker T, Capasso P, Schnyder P et-al. Clinical and radiologic features of pulmonary edema. Radiographics. 1999;19 (6): 1507-31. doi:10.1148/radiographics.19.6.g99no211507 - Pubmed citation
- 2. Khan AN, Al-Jahdali H, Al-Ghanem S et-al. Reading chest radiographs in the critically ill (Part II): Radiography of lung pathologies common in the ICU patient. Ann Thorac Med. 2009;4 (3): 149-57. doi:10.4103/1817-1737.53349 - Free text at pubmed - Pubmed citation