Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is mildly enlarged but unchanged . The mediastinal and hilar contours are similar . Pulmonary vasculature is normal . Streaky atelectasis is seen in the lung bases without focal consolidation . No pleural effusion or pneumothorax is the benefit . Degenerative changes are noted involving both acromioclavicular joints .
    OUTPUT:
    
Mild bibasilar atelectasis .