Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The aorta is tortuous . Mediastinal and hilar contours are otherwise unremarkable . Pulmonary vasculature is not engorged . Blunting of the left costophrenic angle is unchanged , likely reflective of a trace left pleural effusion . Minimal atelectasis is seen in the lung bases without focal consolidation . No pneumothorax is present .
    OUTPUT:
    
No substantial change from the previous study with unchanged blunting of the left costophrenic angle , possibly due to a trace left pleural effusion . Minimal bibasilar atelectasis .