Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours are unchanged , with the heart size appearing top normal . Pulmonary vascularity is within normal limits . There are streaky opacities in the lung bases with crowding of the bronchovascular structures , likely attributable to low lung volumes . No focal consolidation , pleural effusion or pneumothorax is seen . There are mild degenerative changes in the thoracic spine .
    OUTPUT:
    
Low lung volumes with mild streaky bibasilar opacities likely reflective of atelectasis .