Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A central venous catheter terminates in the upper superior vena cava . The heart is normal in size . The mediastinal and hilar contours appear within normal limits . A linear opacity in the left lower lung suggests minor unchanged atelectasis in the lingula . There is no pleural effusion or pneumothorax . Bony structures are unremarkable .
    OUTPUT:
    
No evidence of acute disease .