Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Subtle linear configuration patchy left base opacity is most likely due to atelectasis rather than pneumonia . No pleural effusion or pneumothorax is seen . The cardiac and mediastinal silhouettes are unremarkable . No displaced fracture is seen .
    OUTPUT:
    
Subtle linear configuration patchy left base opacity is most likely due to atelectasis rather than pneumonia