Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable view of the chest demonstrates opacification of most of the right hemithorax with interval increase in right - sided pleural effusion , now quite large , which has significantly increased in size over the course of 10 days , and may be partially loculated . The left lung is essentially clear . Cardiac size remains stable as does the left hilar contour . There is no left pleural effusion .
    OUTPUT:
    
Very large right - sided pleural effusion which may be partially loculated , increased significantly since the prior study , with underlying atelectasis .