Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded . The right lung is clear ; however , the left lung demonstrates an ill - defined opacity in the lower lung fields , with obscuration of the outer margin of the left hemidiaphragm . Cardiomediastinal and hilar contours are unremarkable . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Left lower lobe patchy opacity concerning for pneumonia .