Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The retrocardiac opacity has resolved , and was presumably due to atelectasis . The lungs are clear . There is no pneumothorax . Moderate cardiomegaly despite the projection is unchanged . Unchanged prominence of the hilar contours are likely due to stable mild lymph node enlargement .
    OUTPUT:
    
Clear lungs . Stable moderate cardiomegaly .