Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable upright view of the chest demonstrates low lung volumes , which accentuate bronchovascular markings . Bibasilar opacities most likely represent atelectasis . Hilar and mediastinal silhouettes are unchanged . Heart size top normal . There is no pulmonary edema . No pneumothorax . Descending aorta demonstrates heavy calcifications . Partially imaged upper abdomen is unremarkable .
    OUTPUT:
    
Low lung volumes , bibasilar opacities , most consistent with atelectasis .