Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Rotated positioning . There is probable background COPD . Allowing for rotation , the cardiomediastinal silhouette is grossly unchanged . There is upper zone redistribution , without overt CHF . There is increased opacity at the left lung base , likely a combination of pleural effusion and underlying collapse and / or consolidation . This appears larger than on ___ . The possibility of an associated elevated left hemidiaphragm can not be excluded . Again seen is a small right pleural effusion , probably similar to the prior study on the lateral view . Elsewhere , no focal infiltrate or consolidation . The patient has an azygos lobe , likely incomplete . Given patient rotation , the possibility of some opacification in the azygos lobe can not be excluded , though this could be an artifact due to positioning .
    OUTPUT:
    
Increased density left base , compatible with left pleural fusion and underlying collapse and / or consolidation . The possibility of elevation of left hemidiaphragm can not be excluded . Background COPD . Upper zone redistribution without overt CHF . Small right effusion , not grossly changed . Faint opacification of the right azygos lobe , question artifact due to positioning . Attention to this area on followup films is requested .