Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest . There are low lung volumes compared to prior study . Possibly patchy opacity at the left lung base may represent early pneumonia or atelectasis . The cardiomediastinal silhouette is normal . There is no pleural effusion or pneumothorax . There is bibasilar atelectasis .
    OUTPUT:
    
Low lung volumes . Possibly patchy opacity at the left lung base may represent early pneumonia or atelectasis .