Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . The streaky opacities seen involving the left lower lobe , most consistent with atelectasis . No pleural effusion or pneumothorax is seen .
    OUTPUT:
    
Left lower lobe opacity suggests atelectasis and is new from the prior examination . A previously seen left lower lobe opacity along the fissure is no longer identified on the current study .