Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: All AP upright chest radiograph ___ at 20 :41 is submitted .
    OUTPUT:
    
Hardware now overlies the mid thoracic spine . Overall cardiac and mediastinal contours are likely stable although difficult to assess due to patient rotation . There is improved aeration at the right base and interval appearance of a linear opacity at the left base likely reflecting subsegmental atelectasis . A superimposed infectious process would be much less likely . The left hemidiaphragm is slightly elevated possibly related to prominent air within the splenic flexure . No pulmonary edema . No large effusions or pneumothoraces .