How does pulmonary edema appear on CT?
Initially, pulmonary edema will appear as areas of smooth bilateral interlobular septal thickening, most often in the dependent portions of the lung. As the pulmonary edema worsens, fluid extends from the interstitium into the alveolar spaces. When this occurs, one will begin to see hazy ground glass opacities, often centrally located and symmetric. In very severe cases, pulmonary edema will show symmetric consolidation of the lungs. Asymmetric consolidation is relatively uncommon in pulmonary edema and will usually indicate the presence of a superimposed process such as pneumonia.
Additional findings that suggest pulmonary edema is present include the presence of cardiomegaly and pleural effusions.