Bat wing appearance

Bat wing appearance is a term used in radiology to describe a specific pattern seen on chest radiographs. This pattern is typically associated with pulmonary edema, a condition characterized by excess fluid in the lungs. The term "bat wing" is used because the pattern of opacification seen on the radiograph resembles the wings of a bat.

Overview[edit | edit source]

The bat wing appearance is a radiological sign that is often indicative of pulmonary edema, particularly when it is of rapid onset. This appearance is characterized by symmetrical, bilateral opacities that are most dense in the hilar region (the central portion of the lung where the main bronchi and blood vessels enter), and taper off towards the periphery of the lungs. This pattern of distribution gives the appearance of a bat's wings spread out in flight when viewed on a chest radiograph.

Clinical significance[edit | edit source]

The bat wing appearance on a chest radiograph is a significant finding as it often indicates the presence of pulmonary edema. Pulmonary edema is a serious medical condition where fluid accumulates in the air sacs of the lungs, leading to impaired gas exchange and potentially causing respiratory failure. It is most commonly caused by heart failure, but can also be caused by other conditions such as acute respiratory distress syndrome (ARDS) and kidney failure.

Differential diagnosis[edit | edit source]

While the bat wing appearance is most commonly associated with pulmonary edema, it can also be seen in other conditions. These include pneumonia, particularly when it is bilateral and involves the hilar region, and pulmonary hemorrhage. Therefore, while the bat wing appearance is a useful diagnostic sign, it is not definitive and further investigations are often required to confirm the diagnosis.