Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Lungs appear clear bilaterally without definite signs of pneumonia or CHF . In the lateral view on the retrocardiac region , there is subtle nodular opacity , which in the correct clinical setting could indicate pneumonia . There is also retrocardiac opacity on the frontal view , which raises concern for a hiatal hernia . There is an old right clavicular shaft deformity . Bony structures are otherwise intact .
    OUTPUT:
    
Subtle nodular opacity in the retrocardiac region seen only on lateral view which in the correct clinical setting may represent pneumonia . Possible hiatal hernia .