Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright radiograph of the chest demonstrates a borderline enlarged cardiac silhouette . Multifocal opacities involving the left upper and bilateral lower lobes have improved since the prior examination but are persistent . No definite pleural effusion or pneumothorax is identified . Median sternotomy wires are intact and well aligned . Hilar contours are unchanged .
    OUTPUT:
    
Multifocal opacities , improved since the prior examination , but persistent . This likely represents resolving pneumonia , though recurrent or persistent infection is not excluded .