Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A central venous catheter terminates in the right atrium . The cardiac , mediastinal and hilar contours appear stable , including tortuosity of the thoracic aorta . The posterior costophrenic sulcus on the left is obscured , which suggests a small pleural effusion and patchy associated opacity in the adjacent parenchyma , which is most commonly due to atelectasis . A metallic stent and surgical clips project over the right upper quadrant . Suture anchors are present in the right humeral head .
    OUTPUT:
    
Right posterior basilar density suggesting a possible pleural effusion with patchy atelectasis , although pneumonia is not entirely excluded .