Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is mildly enlarged with a left ventricular predominance , unchanged . The mediastinal and hilar contours are similar . Pulmonary vasculature is not engorged . Patchy opacities are re - demonstrated in the lung bases , potentially atelectasis though aspiration can not be excluded . No pneumothorax or pleural effusion is identified . Sub acute left - sided rib fractures are again .
    OUTPUT:
    
Patchy bibasilar airspace opacities , as seen previously , findings which may reflect atelectasis though aspiration can not be excluded .