Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are low lung volumes . This accentuates the size of the cardiac and mediastinal silhouettes , the heart size is likely mildly enlarged but unchanged . The aorta is tortuous . There is crowding of the bronchovascular structures , but no overt pulmonary edema . Streaky opacities at lung bases likely reflect atelectasis . No pleural effusion or pneumothorax is seen . Degenerative changes are also noted in the left glenohumeral joint .
    OUTPUT:
    
Low lung volumes which limits assessment of the lung bases . Probable bibasilar atelectasis .