Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . there is no pleural effusion or pneumothorax . The cardiomediastinal silhouette and pulmonary vasculature is unremarkable . Minimal right infrahilar opacity is seen , not definitively identified on prior examinations , which may represent vascular crowding or atelectasis , though focal consolidation is not entirely excluded . Vague new retrocardiac opacity is also seen , which may be related to atelectasis , though aspiration is not excluded .
    OUTPUT:
    
1 . More prominent right infrahilar and retrocardiac opacities than seen on most recent comparison may represent aspiration or atelectasis .