Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is borderline enlarged . Mediastinal and hilar contours are within normal limits . Pulmonary vasculature is normal . Minimal patchy opacity in the left lung base likely reflects atelectasis . No focal consolidation , pleural effusion or pneumothorax is present . No acute osseous abnormalities identified .
    OUTPUT:
    
Left basilar atelectasis . No radiographic evidence for pneumonia .