Pulmonary edema: an anatomic, pathophysiologic, and roentgenologic analysis.

Pulmonary edema is a complex subject. Knowledge of the anatomy of the distal air space is essential to the understanding of the pathophysiology of pulmonary edema.Histological evaluation of experimental pulmonary edema in dogs by Staub et al using the quick freeze method indicates that the edema begins in the interstitium. An x-ray examination at this time would be interpreted as negative or normal. Similarly, with only partial filling of the alveolus, a negative reading may be given.A method for classification of pulmonary edema by mechanisms is reviewed.Cases of pulmonary edema caused by different etiologies are presented for an overview of the problem.