Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since the prior exam , there is a new dense opacity in the posterior left lower lobe , most consistent with pneumonia . It is difficult to exclude a small amount of pleural fluid on the left . A hazy linear opacity on the right may represent atelectasis or second focus of pneumonia . There is no right pleural effusion , pulmonary edema , or pneumothorax . The cardiomediastinal silhouette is normal .
    OUTPUT:
    
New left lower lobe pneumonia and possible new subtle right lower lobe pneumonia .