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 ___ . On the frontal exam , there is increased patchy opacity at the right lung base obscuring the right heart border which is less conspicuous on the lateral view . Elsewhere , the lungs are clear , costophrenic angles are sharp . Cardiomediastinal silhouette is within normal limits . Osseous and soft tissue structures are unchanged . Changes at the right humeral head are less clearly seen on the current exam .
    OUTPUT:
    
Increased opacity in the right middle lobe , more conspicuous on the frontal exam and potentially due to atelectasis ; however , underlying pneumonia is not excluded .