Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal and hilar contours are normal . A small left pleural effusion has slightly decreased since the prior study . Minimal left basilar atelectasis is seen . Right lung is well expanded and clear . No pulmonary edema , consolidation or pneumothorax is seen .
    OUTPUT:
    
Small left pleural effusion , slightly smaller since ___ . Mild left basilar atelectasis .