Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is mild to moderately enlarged . The aorta is unfolded . Widening of the superior mediastinum is likely due to supine positioning , AP technique , and low lung volumes . Crowding of the bronchovascular structures is present without overt pulmonary edema . Patchy opacities are noted in the lung bases , likely reflective of atelectasis . No large pleural effusion or pneumothorax is identified . There are no acutely displaced fractures . Degenerative changes are seen involving both acromioclavicular joints and within the thoracic spine .
    OUTPUT:
    
Low lung volumes with bibasilar atelectasis .