Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The aorta is mildly unfolded . The hilar contours are unremarkable . There is no pulmonary vascular congestion . Widening of the superior mediastinum may be due to vascular structures and mediastinal fat . There is no pulmonary edema . Streaky opacity within the lung bases likely reflect atelectasis . No pleural effusion or pneumothorax is seen . No pneumomediastinum is demonstrated . Multilevel degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
Mild bibasilar atelectasis . No definite evidence for pneumomediastinum or pneumothorax . Widening of the mediastinum superiorly likely reflects underlying vascular structures and mediastinal fat . If there is continued concern , chest CT can be obtained for further assessment .