Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest demonstrate clear lungs . There has interval improvement in aeration of the left lung . The cardiomediastinal and hilar contours are stable . There is no pneumothorax or pleural effusion . Pleural surfaces are unremarkable .
    OUTPUT:
    
Normal chest radiograph . Specifically , no evidence of pneumonia .