Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Heart size is mildly enlarged . Mediastinal contours are unchanged . Linear and patchy bibasilar airspace opacities likely reflect atelectasis , similar to the prior exam . Pulmonary vascularity is not engorged . No pleural effusion or pneumothorax is clearly identified . Mild biapical pleural thickening is present . Clips are seen in the right upper quadrant of the abdomen compatible with prior cholecystectomy .
    OUTPUT:
    
Mild bibasilar atelectasis , relatively unchanged compared to the prior study .