Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear without focal consolidation . No pleural effusion or pneumothorax is seen . The cardiac and mediastinal silhouettes are stable . The previously described linear thin density projecting over the right side of the heart just inferior to the right mainstem bronchus on the prior study is not seen on the current study and may have been external to the patient . .
    OUTPUT:
    
Previously seen linear density projecting just inferior to the right mainstem bronchus is no longer seen and may have been external to the patient .