Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-erect chest radiograph ___ at 05 : 16 is submitted .
    OUTPUT:
    
Tubes and lines are unchanged in position . Heart remains stably enlarged . Lung volumes remain low . There is interval appearance of mild pulmonary and interstitial edema . Left retrocardiac opacity remains and may reflect a combination of partial lower lobe atelectasis in the setting of a layering effusion . No obvious pneumothorax . Hardware overlies the mid to lower cervical spine .