'Batwing' appearance on X-ray chest is seen in:

In Cardiogenic pulmonary edema: "Butterfly" or "Bat wing" appearance (i.e., consolidated hilum + uninvolved lung coex) on CXR. The central/perihilar distribution is supposed to be due to increased fluid accumulation in central alveoli due to their increased elastin content. Chest radiograph shows: Cardiogenic pulmonary edema Non-cardiogenic pulmonary edema Enlarged cardiac silhouette Hea size is normal Vascular redistribution Alveolar infiltrates are distributed more uniformly Interstitial thickening and perihilar alveolar infiltrates Pleural effusions are common Pleural effusions are uncommon