Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A new right internal jugular central venous catheter terminates in the superior vena cava . The lung volumes are low . The cardiac , mediastinal and hilar contours appear stable . A retrocardiac opacity appears increased . Atelectasis or developing pneumonia are differential diagnoses for this appearance . Known pulmonary nodules are not optimally visualized on the portable radiography . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Increasing retrocardiac opacity , atelectasis versus pneumonia . New central venous catheter terminating in the superior vena cava ; no pneumothorax .