Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . Left chest wall pacer device is again seen with leads extending to the region the right atrium and right ventricle as on prior . Midline sternotomy wires are again noted . There is subtle lower lung opacity noted bilaterally which could represent mild atelectasis though early pneumonia or aspiration is difficult to exclude in the correct clinical setting . Mild hilar congestion is suspected . There is no frank pulmonary edema . No large effusions are seen . No pneumothorax . Cardiomediastinal silhouette is unchanged . Bony structures appear intact .
    OUTPUT:
    
Subtle lower lung opacities likely atelectasis versus early pneumonia in the correct clinical setting . Mild hilar congestion .