Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are hyperinflated but clear without consolidation , effusion , or edema . There is a somewhat rounded retrocardiac opacity in the frontal view likely projecting over the spine on the lateral view . This may be related to a hiatal hernia , although no definitive lucency within the opacity , or potentially a Bochdalek 's hernia Old healed mid left clavicular fracture is noted .
    OUTPUT:
    
No acute cardiopulmonary process . Relatively rounded retrocardiac opacity most likely due to a hiatal hernia but this is not definitive based on this chest x-ray . Correlation to confirm this finding with prior imaging is suggested if possible . Alternatively , additional nonurgent imaging could be considered .