Which classic CXR finding is associated with pulmonary edema?

The classic chest X-ray (CXR) finding associated with pulmonary edema is characterized by the "bat's wing" appearance, which refers to the symmetrical opacification of the perihilar regions of the lung. This pattern arises due to the accumulation of fluid in the interstitial and alveolar spaces, primarily affecting the central part of the lungs. As fluid accumulates, it displaces air and creates a characteristic radiographic appearance that resembles the wings of a bat spreading outwards from the hilum.

In pulmonary edema, fluid primarily floods the alveoli and connective tissue, leading to the classic bilateral fluffy opacities that can be seen in the lower and central parts of the lungs on a chest radiograph. This specific finding indicates a high likelihood of congestive heart failure or other causes of pulmonary edema.

Other options present different pathologies. For instance, hyperinflation of lung fields is often seen in conditions like asthma or emphysema, while a reticular pattern in the lower lobes may suggest interstitial lung disease rather than edema. Air bronchograms are indicative of alveolar consolidation due to pneumonia but are less specific to pulmonary edema. Therefore, the "bat's wing" appearance is the hallmark finding for pulmonary edema on a C