Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single upright frontal image of the chest shows a large left pleural effusion with associated atelectasis . Underlying airspace disease in the left lower lobe can not be excluded . Hazy opacification of the right base is likely atelectasis . There is no pneumothorax . The size of the cardiac silhouette is somewhat obscured by the effusion , but appears normal . The mediastinal and hilar contours are normal .
    OUTPUT:
    
Large left pleural effusion ; can not excluded underlying airspace disease in the left lower lobe .