Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Stable cardiomegaly with permanent pacemaker in place . Low lung volumes accentuate the pulmonary vasculature . With this limitation in mind , there is no definite evidence of congestive heart failure . Patchy opacities are present at both lung bases and there is a suggestion of a small left pleural effusion .
    OUTPUT:
    
Patchy bibasilar opacities , likely due to atelectasis . Differential diagnosis includes aspiration and early , developing pneumonia . Short - term followup radiographs may be helpful in this regard .