Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest film ___ at 14 40 is submitted .
    OUTPUT:
    
Stable subtle patchy opacity at the right medial lung base may reflect an area of atelectasis or aspiration pneumonia . Clinical correlation is advised . Fiducial marker at the left lung apex unchanged . Prominent soft tissue in the right medial lung apex most likely represents vascular structures accentuated due to patient rotation on the current study . No large effusions . No pneumothorax . No evidence of pulmonary edema . Overall cardiac and mediastinal contours are unchanged .