Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Interval placement of a nasogastric tube , which terminates in the stomach . Stable , borderline cardiomegaly . Mediastinal and hilar contours are normal . Slight interval improvement in low lung volumes bilaterally . Persistent retrocardiac opacity suggests atelectasis . Stable opacity in the right cardiophrenic sulcus could represent atelectasis or pneumonia . Interval resolution of small left pleural effusion . No pneumothorax .
    OUTPUT:
    
Slight interval improvement in lung volumes bilaterally . Stable bibasilar opacities likely reflect atelectasis , but superimposed infection can not be excluded .