Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiograph demonstrates obscuration of the right heart border concerning for infection . The remainder of the lungs are clear . Cardiomediastinal and hilar contours are within normal limits . There is no overt pulmonary edema . There is no pleural effusion . Osseous structures are without acute abnormality .
    OUTPUT:
    
Obscuration of the right heart border which may reflect a right middle lobe infectious process in the correct clinical setting . Alternatively , this may reflect atelectasis of the right middle lobe .