Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Subtle patchy opacity over the left lung base raises concern for pneumonia . Additionally , there is subtle opacity projecting over the right upper lung , which may be additional site of infection . Given that there are no priors for comparison , can not discern whether findings have improved , stayed the same or worsened since the prior study . No pleural effusion or pneumothorax is seen . The cardiac and mediastinal silhouettes are unremarkable .
    OUTPUT:
    
Bilateral , subtle patchy opacities , as above , concerning for multifocal pneumonia . In the absence of priors currently available for comparison , can not determine whether findings have increased , decreased or remained the same . Comparison with prior studies would be helpful for further evaluation .