Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is unchanged , and remains top normal . The aorta remains tortuous and diffusely calcified . The hilar contours are unchanged . Previous pattern of mild pulmonary vascular congestion has essentially resolved . There is minimal patchy opacities in the lung bases most likely reflective of atelectasis . No focal consolidation , pleural effusion or pneumothorax is identified . There are mild degenerative changes in the thoracic spine .
    OUTPUT:
    
Minimal bibasilar atelectasis .