Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes . Interval increase in retrocardiac opacity is likely increased left lower lobe atelectasis . New mild right basilar atelectasis . No additional focal opacity , pneumothorax , pleural effusion , or pulmonary edema . Heart size , mediastinal contour and hila are normal . Mildly nondilated tortuous aorta . Mild degenerative change of the thoracic spine without additional bony abnormality .
    OUTPUT:
    
Interval increase in bibasilar atelectasis .