Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are normally expanded . Faint opacity at the left base may represent atalectasis or early infiltrate . The cardiomediastinal silhouette , hilar contours and pleural surfaces are normal . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Atalectasis vs early infiltrate at the left base