Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright portable chest radiograph was obtained . A dual - lead pacer is in unchanged position with lead tips extending to the right atrium and right ventricle . Retrocardiac opacity may indicate a left pleural effusion and left basilar consolidation . The lungs are hyperlucent , which could indicate underlying emphysema . The right lung is clear . Patient is rotated to the left . Atherosclerotic calcification along the thoracic aorta noted . Bony structures appear intact .
    OUTPUT:
    
Left lung base opacity likely effusion and consolidation . Overall , no significant change from prior exam .