Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is new increased retrocardiac atelectasis and a developing pneumonia can not be excluded . Otherwise , large hiatal hernia remains stable . The right hemithorax is clear . Recently noted nodular opacities in the left upper lobe are better visualized on dedicated chest CT from ___ . No acute fractures are identified .
    OUTPUT:
    
New opacity in the left lower lobe is likely suggestive of atelectasis . However , a developing pneumonia can not be excluded . Large hiatal hernia persists .