Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear without focal consolidation to suggest pneumonia . Atelectasis is seen at the left lung base . There is no pleural effusion or pneumothorax . The heart size is top normal . A percutaneous biliary drain and metallic common bile duct stent are noted .
    OUTPUT:
    
Left basilar atelectasis .