Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest are compared to previous exam from ___ and ___ . When compared to prior , there has been interval resolution of the opacity in the anterior segment of one of the upper lobes . However , when compared to older normal chest x-ray from ___ , there may be persistnet subtle opacity at the right lung base laterally , potentially within the right lower lobe . Posterior costophrenic angles are sharp . The cardiac silhouette which is enlarged is stable . Osseous and soft tissue structures are unremarkable .
    OUTPUT:
    
Interval improvement of opacity is identified in the upper lobe since most recent prior exam . There is , however , subtle persistent opacity at the right lung base when compared to older , normal chest x-ray from ___ which could represent atelectasis or developing infiltrate , clinical correlation recommended .