Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A PICC line terminates in the left brachiocephalic vein . The lung volumes are low . The cardiac , mediastinal and hilar contours appear stable . There is no pleural effusion or pneumothorax . Posterior basilar opacity in the left lower lobe could be seen with atelectasis or possibly aspiration . A left mid lung opacity has resolved .
    OUTPUT:
    
Patchy posterior left basilar opacity , probably due to atelectasis , although a small focus of aspiration is possible .