Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been interval improvement in bilateral pleural effusions with none currently seen . The lungs are hyperinflated suggesting underlying chronic obstructive pulmonary disease . There is diffuse increase in interstitial marking , possibly related to COPD . More focal left base opacity is seen , which could be due to pneumonia or aspiration . No large pleural effusion or pneumothorax is seen . The cardiac silhouette is not enlarged . The aorta is calcified and tortuous .
    OUTPUT:
    
Left base opacity raises concern for pneumonia or aspiration .