Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest are compared to prior exam from ___ . On the frontal , again seen are bibasilar opacities suggestive of atelectasis versus scar . There is , however , more density projecting over the spine on the lateral view inferiorly compared to prior , potentially localizing to the left on the frontal exam . There is blunting of the lateral costophrenic angle on the left suggesting a scar given interval stability . Superiorly , the lungs remain clear . Cardiomediastinal silhouette remains stable , noting moderate - to - large hiatal hernia . Osseous and soft tissue structures are unremarkable .
    OUTPUT:
    
Moderate - sized hiatal hernia . Bibasilar scarring versus atelectasis . Increased density projecting over the spine which could be due to additional atelectasis ; however , pneumonia is also possible .