Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Again seen is retrocardiac opacity which now has air -fluid levels which are most likely related to gastric pull - through . The lung fields are otherwise clear and there is no pleural effusion or pneumothorax . Cardiomediastinal silhouette is unremarkable . Calcific densities overlying left ribs are stable from prior exam .
    OUTPUT:
    
Stalbe retrocardiac opacity , now with air - fluid levels which is most likely related to to gastric pull - through .