Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low with mild widening of the cardiomediastinal silhouette . There is mild pulmonary vascular congestion . There is a left retrocardiac opacity extending into the left perihilar region concerning for an infectious process .
    OUTPUT:
    
Left basilar opacities concerning for pneumonia . Mild pulmonary vascular congestion .