Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . Midline sternotomy wires , AICD and prosthetic cardiac valve again noted . There has been interval removal of the right IJ central venous catheter . A short metallic stent projects over the mediastinum which corresponds to a stent within the proximal left subclavian artery . Patient 's chin obscures the superior mediastinum . There is suboptimal inspiratory effort which limits assessment . There is mild pulmonary edema with hilar congestion noted . No large effusion can be seen . No large pneumothorax . No convincing signs of pneumonia . Heart size can not be assessed . Mediastinal contour appears grossly unchanged . Bony structures are intact .
    OUTPUT:
    
Mild pulmonary edema . Limited exam .