Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . Mediastinal and hilar contours are unremarkable . The pulmonary vasculature is normal . Persistent small left pleural effusion is noted , with slight interval worsening of adjacent left basilar opacity likely reflecting compressive atelectasis . There is no right - sided pleural effusion , and the right lung is clear . No pneumothorax is visualized . There are no acute osseous abnormalities .
    OUTPUT:
    
Persistent small left pleural effusion with slight worsening of adjacent left basilar opacity likely reflective of compressive atelectasis .