Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single AP upright portable view of the chest was obtained . There is slight blunting of the left costophrenic angle which may be due to a pleural effusion . Evidence of hiatal hernia is again seen . No definite focal consolidation is seen . There is no evidence of pneumothorax . The cardiac and mediastinal silhouettes are stable and unremarkable . Bilateral vagal nerve stimulators are again seen , without significant change in position .
    OUTPUT:
    
Slight blunting of the left costophrenic angle may be due to trace pleural effusion . Streaky left base retrocardiac opacity most likely relates to atelectasis / scarring and was also seen on the prior study .