Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear unchanged . There is mild elevation of the left hemidiaphragm with improvement in opacification at the left lung base . Elsewhere , the lungs remain clear . There is probably a small pleural effusion on the left but no suggestion of one on the right side .
    OUTPUT:
    
Mild elevation of the left hemidiaphragm and suspicion for possible very small left pleural effusion , but generally improvement in opacification at the left lung base .