Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . Midline sternotomy wires and mediastinal clips are again noted . The heart remains moderately enlarged . There are diffuse pulmonary airspace opacities right greater than left , concerning for pulmonary edema , though difficult to exclude a superimposed pneumonia . No large effusion is seen . No pneumothorax . Mediastinal contour is grossly unchanged . Bony structures are intact . The superior most sternotomy wire appears fragmented as on prior .
    OUTPUT:
    
Moderate cardiomegaly with severe pulmonary edema . Difficult to exclude a component of pneumonia .