Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is mildly enlarged but unchanged . Mediastinal and hilar contours are unremarkable . Pulmonary vasculature is normal . There is a trace left pleural effusion , new compared to the previous study . No pneumothorax is identified . No acute osseous abnormalities are visualized .
    OUTPUT:
    
Trace left pleural effusion , new from prior .