Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since ___ , a left pleural effusion is smaller . The mediastinum is midline suggesting a component of collapse . The left and right lungs are otherwise clear . The heart is enlarged but partially obscured by the effusion . There is no pneumothorax .
    OUTPUT:
    
Interval decrease in size of left pleural effusion . No pneumothorax .