Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette is stable and unremarkable . Again noted is a left perihilar opacity , very slightly decreased since the prior examination . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Slight improvement an heterogeneous left perihilar and basilar opacities , likely due to an acute infectious process .