Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . The hilar and mediastinal contours are normal . There is mild bibasilar atelectasis . There is no large pleural effusion or pneumothorax . Apparent leftward displacement of the trachea may be positional . The visualized osseous structures are unremarkable .
    OUTPUT:
    
No acute intrathoracic abnormalities identified . Apparent leftward displacement of the trachea is likely due to patient rotation , but correlation with physical exam findings may be helpful to exclude thyroid enlargement if warranted clinically .