Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is mildly enlarged . The mediastinal and hilar contours are unchanged within normal limits . Lungs are clear . Pulmonary vasculature is normal . Blunting of the left costophrenic angle is new and compatible with a small pleural effusion . No pneumothorax is present . Mild loss of height of a mid thoracic vertebral body is unchanged .
    OUTPUT:
    
Small left pleural effusion . No evidence of congestive heart failure .