Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A rounded retrocardiac opacity is not well seen on the AP view but likely reflects a hiatus hernia . This would be an atypical appearance for pneumonia but further characterization with CT may be helpful . The cardiomediastinal contour is otherwise normal . There is no pneumothorax or pleural effusion . Borderline loss of vertebral body height in 2 of the mid thoracic vertebrae are likely within the range for normal .
    OUTPUT:
    
A rounded retrocardiac opacity has somewhat distinct borders and may represent a hiatus hernia or an atypical appearance for pneumonia , however a more focal lesion can not be excluded . CT chest may be helpful to clarify , alternatively followup with repeat chest radiograph in ___ weeks following completion of treatment to re-evaluate would be recommended .