Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . Midline sternotomy wires and prosthetic cardiac valve noted . There is stable mild cardiomegaly with moderate pulmonary edema . Small bilateral pleural effusions are likely present . No pneumothorax . Difficult to exclude a superimposed subtle pneumonia . Bony structures are intact .
    OUTPUT:
    
Pulmonary edema , stable cardiomegaly , likely small pleural effusions . Difficult to exclude superimposed pneumonia .