Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Two views of the chest were obtained and there is no comparison for review . The lungs are low in volume but clear aside from retrocardiac atelectasis . There is no pleural effusion or pneumothorax . The heart is normal in size , normal cardiomediastinal contours .
    OUTPUT:
    
Minimal left basal atelectasis .