Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are normal . Pulmonary vasculature is not engorged . Small left pleural effusion is present , perhaps slightly decreased in size compared to the prior exam . There is associated atelectasis in the left lower lobe . The right lung is clear . No pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Small left pleural effusion , perhaps slightly decreased in size from the prior study , with adjacent left lower lobe atelectasis .