Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes . Bibasilar opacities likely represent atelectasis . No focal consolidations . The pulmonary vasculature is normal . The right mediastinum appears enlarged , which may be rotational . Moderate - sized hiatal hernia is unchanged . No pneumothorax .
    OUTPUT:
    
1 . Low lung volumes and bibasilar atelectasis , but no focal consolidations . 2 . Right mediastinal enlargement , which may be rotational , but repeat radiographs with improved positioning should be obtained . 3 . Moderate - sized hiatal hernia .