Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiograph demonstrate a large left pleural effusion . Relative to prior examination dated ___ , heart size is decreased . The left heart border is obscured making assessment of heart size difficult . There is no overt pulmonary edema . The visualized lungs are without a focal opacity convincing for pneumonia . There is no pneumothorax . Osseous structures are without an acute abnormality .
    OUTPUT:
    
Large left pleural effusion . Relative to prior examination dated ___ , cardiac size appears decreased .