Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . Calcification is noted of the aortic knob with mild unfolding of the descending thoracic aorta . There is a small left pleural effusion versus pleural thickening . There is no right pleural effusion . There is no pneumothorax . Lungs are hyperexpanded with flattened hemidiaphragms and enlarged retrosternal air space , consistent with COPD . No focal consolidations concerning for pneumonia . A small opacity in the left mid lung may represent superimposition of shadows . The upper abdomen is unremarkable . Degenerative changes are seen in the thoracic spine .
    OUTPUT:
    
Small left pleural effusion versus pleural thickening without focal consolidation concerning for pneumonia . Hyperinflation . Apparent focal density in the left mid lung .