Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . Mild calcifications are demonstrated within the aortic knob . The mediastinal and hilar contours are unremarkable . The pulmonary vascularity is normal . The lungs are clear . A small left pleural effusion is present , which was visualized on the prior CT abdomen from ___ . No pneumothorax is identified . No acute osseous abnormalities are seen .
    OUTPUT:
    
Small left pleural effusion similar to that seen on the prior CT from ___ .