Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since the prior study , there is little change in opacification of the right lung base , likely combination of atelectasis and effusion , moderate cardiomegaly , and location of pacemaker leads and prosthetic aortic and tricuspid valves . Infection at the right lung base can not be excluded . There is mild pulmonary vascular congestion .
    OUTPUT:
    
Unchanged mild cardiomegaly , mild pulmonary vascular congestion , and small right pleural effusion with adjacent right basilar opacification , likely atelectasis but infection can not be excluded .