Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . Mediastinal and hilar contours are unremarkable . Pulmonary vasculature is normal . There is minimal atelectasis in the left lung base . Remainder of the lungs are clear . No focal consolidation , pleural effusion or pneumothorax is present . There are no acute osseous abnormalities .
    OUTPUT:
    
Minimal left basilar atelectasis . Normal mediastinum .