Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal and unchanged . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . There is bibasilar atelectasis . Lungs are otherwise clear . No pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
No acute intrathoracic abnormality .