Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest were obtained . Subtle left perihilar opacity similar as compared to the prior study although unclear whether artifactual or a true consolidation . No new consolidation is seen . There is no pleural effusion or pneumothorax . The cardiac and mediastinal silhouettes are unremarkable .
    OUTPUT:
    
No significant interval change . Mild left perihilar opacity may be artifactual ; however , in the appropriate clinical setting , a subtle pneumonia is not entirely excluded . No new focal consolidation .