Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable chest radiograph demonstrates a large rounded opacity in the left lower lung , correlating with known left lung mass , better visualized on the ___ PET - CT . No focal opacification concerning for pneumonia . Bibasilar atelectasis is evident . Coarse linear interstitial markings in left upper lobe may reflect emphysematous change . There is no pneumothorax or pleural effusion . Prominent pericardial fat pads are evident ; otherwise , cardiomediastinal contours are normal .
    OUTPUT:
    
No pneumothorax . Large left lower lobe mass , better evaluated on prior CT .