Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to prior chest radiographs from ___ , moderate left pleural effusion with associated left basilar atelectasis is unchanged . Retrocardiac opacity , which likely represents atelectasis , though pneumonia can not be definitively excluded . There is no central vascular congestion or overt pulmonary edema . Mild tortuosity and unfolding of the thoracic aorta with calcification at the aortic knob . Mild cardiomegaly is stable . Left - sided cardiac pacing device with leads following their expected courses to the right atrium and ventricle . Right - sided double - lumen hemodialysis catheter with tip terminating in the right atrium .
    OUTPUT:
    
1 . Retrocardiac opacity , which likely represents atelectasis , though pneumonia can not be definitively excluded in the proper clinical setting . 2 . Stable moderate left pleural effusion with associated left basilar atelectasis . 3 . Stable mild cardiomegaly .