Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart remains mildly enlarged . There is a retrocardiac opacity consistent with a hiatal hernia . No large effusion or pneumothorax . No signs of pneumonia or edema . Mediastinal contour is stable . Bony structures are intact .
    OUTPUT:
    
Stable cardiomegaly and retrocardiac opacity consistent with hiatal hernia . No acute findings .