Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest . There is volume loss in the left hemithorax with elevation of left hemidiaphragm and of the left hilum . Findings are compatible with left upper lobectomy . The lungs are clear . The cardiomediastinal silhouette is within normal limits . Deformity of the posterior left sixth rib is again seen .
    OUTPUT:
    
Postoperative changes of left upper lobectomy . No superimposed acute cardiopulmonary process .