Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiomediastinal and hilar contours are normal . There is no pneumothorax . Possible , increased retrocardiac opacity raises concern for left lower lobe pneumonia . Mild blunting of the left costophrenic angle suggests a small left pleural effusion .
    OUTPUT:
    
Possible left lower lobe pneumonia with a small left pleural effusion .