Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is no pneumothorax or pneumomediastinum . The cardiomediastinal silhouette is normal . A small right pleural effusion is unchanged . Since the prior radiograph , there has been increased nodular peribronchial opacification , most readily explained by chronic aspiration . Mild hazy opacification at the left base is unchanged and likely represents chronic atelectasis .
    OUTPUT:
    
1 . No pneumothorax or pneumomediastinum . 2 . Increasing peribronchial opacification at the right base likely represents aspiration , possibly pneumonia .