Which pattern of infiltrate is referred to as a 'Batwing pattern'?

The term 'Batwing pattern' describes a distinct radiological appearance commonly associated with pulmonary edema. This pattern emerges due to the accumulation of fluid in the interstitial and alveolar spaces of the lungs, leading to a characteristic bilateral and symmetrical distribution of infiltrates. On chest X-rays, this often manifests as a "butterfly" or "batwing" shape, where both central and peripheral regions of the lungs display increased opacity.

In the context of pulmonary edema, the fluid typically collects in the perihilar areas, creating a pattern that resembles the outstretched wings of a bat. This visual representation helps clinicians in diagnosing conditions that lead to fluid overload in the lungs, such as heart failure. While atelectasis, ARDS/IRDS, and pulmonary embolism present their own unique radiographic features, they do not produce the specific batwing appearance associated with pulmonary edema.