Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Normal heart size , mediastinal and hilar contours . Previously seen opacity on the right is no longer visualized . The ring opacity previously seen now more convincingly appears to be normal vessels . The lungs remain hyperexpanded but clear . No pleural effusion or pneumothorax .
    OUTPUT:
    
Previously seen right mid lung opacity and left ring opacity appears to have been artifactual . Hyperexpanded lungs , otherwise normal chest radiograph .