Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Retrocardiac opacity is again noted which is compatible with hiatal hernia . There is bibasilar atelectasis also noted . Subtle ground - glass opacity in the left lower lung could also represent aspiration versus pneumonia in the correct clinical setting . Upper lungs appear well aerated . The heart size is difficult to assess . Mediastinal contour is unchanged . Bony structures are intact .
    OUTPUT:
    
Hiatal hernia , bibasilar atelectasis , difficult to exclude an early pneumonia in the left lower lung in the correct clinical setting .