Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since prior , volumes are lower , but lungs are grossly clear . There is minimal linear atelectasis in the right lower lung zone . The cardiomediastinal and hilar contours are stable . There is no pleural effusion or pneumothorax . Pleural surfaces are unremarkable .
    OUTPUT:
    
No evidence of pneumonia .