Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-erect chest radiograph ___ at 04 : 28 is submitted .
    OUTPUT:
    
Right subclavian PICC line and tracheostomy tube are unchanged in position . Left retrocardiac mass is again noted . No pulmonary edema . Improved aeration at both lung bases . Cardiac and mediastinal contours are difficult to assess given the marked patient rotation on the current study . No obvious pneumothorax . Old left - sided rib fractures with associated pleural thickening are better visualized on this exam .