Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . There are subtle retrocardiac opacity which in the correct clinical setting may reflect pneumonia . Otherwise the lungs appear clear . Mild prominence of the hilar markings may reflect a component of central airways inflammation in the correct clinical setting . No large effusion or pneumothorax . Heart and mediastinal contours are normal . Bony structures are intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
Retrocardiac opacity may reflect pneumonia . Mild prominence of central bronchovascular markings could reflect central airways inflammation .