Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: In comparison with the CT examination of ___ , there has been substantial opacification of the left hemithorax with shift of the mediastinal contents to the left . This is consistent with severe volume loss in the left lung . The right lung is hyperexpanded and essentially clear .
    OUTPUT:
    
Collapse of most of the left lung with mediastinal shift . This information was noted at 11 :20 a .m . and telephoned at 11 :22 a .m . to Dr . ___ .