Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are unchanged and within normal limits . Subsegmental atelectasis is seen within the left lower lobe . Lungs are otherwise clear . Pulmonary vasculature is normal . No pleural effusion or pneumothorax is demonstrated . No acute osseous abnormality is detected .
    OUTPUT:
    
No acute cardiopulmonary abnormality .