Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Sternotomy wires and mediastinal clips are unchanged . There has been interval removal of the right IJ central venous catheter . The heart size is at the upper limits of normal . The mediastinal and hilar contours are unremarkable . A small left pleural effusion is present , prior right effusion has cleared . There is no overt evidence of edema or failure . No pulmonary consolidation is present . There is no pneumothorax .
    OUTPUT:
    
Small persistent left pleural effusion .