Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Chronic small bilateral pleural effusions have increased . Despite vascular crowding , mild pulmonary edema likely persists . The left lower lobe airspace opacity has increased , and is worrisome for pneumonia or atelectasis . The heart and mediastinum are magnified by the projection . Sternotomy wires and spinal fixation hardware are again noted .
    OUTPUT:
    
Increased left lower lobe opacity may be due to atelectasis or pneumonia . Increased small bilateral pleural effusions . Stable mild pulmonary edema .