Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patchy left lower lobe opacity is seen , raising concern for pneumonia . This opacity appears less extensive as compared to the prior chest radiograph from ___ . Bibasilar atelectasis is seen . No pleural effusion or pneumothorax is seen . The cardiac and mediastinal silhouettes are stable .
    OUTPUT:
    
Patchy left lower lobe opacity concerning for pneumonia .