Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours are stable . There is similar moderate relative elevation of the left hemidiaphragm . Streaky opacities are present in the left lower lung , but mostly the lungs are much better aerated and this finding could be seen with patchy associated atelectasis . The right lung is clear . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Left lower lung opacity , although more suggestive of atelectasis or scarring in the presence of an elevated hemidiaphragm than pneumonia . The possibility of an infectious cause is not entirely excluded , however .