Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Diffuse bilateral reticular opacities are slightly improved from prior examination . As before , these are slightly more prominent in the right upper lobe . Probable small right pleural effusion is unchanged . Coronary artery bypass grafting changes , with median sternotomy wires and mediastinal clips . There is persistent mild cardiomegaly and calcification at the aortic arch .
    OUTPUT:
    
Slight improvement in diffuse pulmonary opacities , suggesting decrease in edema , with probable superimposed pneumonia .