Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . The cardiac silhouette is borderline enlarged . A retrocardiac opacity is new since the prior examination , and in the appropriate clinical context , is consistent with left lower lobe pneumonia . Left basilar opacity is chronic and similar to the examination from ___ . A small pleural effusion may be present . Right infrahilar opacity is likely representative of crowding of vascular structures given low lung volumes . There is no pneumothorax .
    OUTPUT:
    
Left lower lobe pneumonia .