Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are normal . Lung volumes are low . Minimal atelectasis in the left base is noted . No focal consolidation , pleural effusion or pneumothorax is present . Pulmonary vascularity is normal . Partially imaged are bilateral humeral head prostheses .
    OUTPUT:
    
Mild left basilar atelectasis .