Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is top normal . The lung volumes are low , resulting in bronchovascular crowding . Moderate bibasilar atelectasis is present , with a left retrocardiac opacity which may reflect atelectasis versus small consolidation . There is no pneumothorax or pleural effusion .
    OUTPUT:
    
Moderate left lower lobe atelectasis . Infection in this region can not be excluded .