Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is slightly enlarged . Mediastinal and hilar contours are normal . The lungs demonstrate a consolidative airspace opacity affecting primarily the left lung base . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
1 . Left lower lobe pneumonia . 2 . Mildly enlarged heart , possibly within normal limits , but a pericardial effusion can not be excluded ; correlate with ultrasound findings .